You had a plan.
You knew what time you were leaving. You knew where you were going. You had mentally arranged the rest of your day around it.
Then someone says:
“Actually, let’s do this instead.”
It isn’t a catastrophe. Nobody canceled Christmas. The building isn’t on fire.
And yet something inside your brain responds:
“I’m sorry. We are doing WHAT?”
Maybe you’re irritated. Maybe you suddenly feel anxious or overwhelmed. Maybe you need a few minutes before you can even think about the new plan. Or perhaps you agree to the change perfectly politely while your brain spends the next 20 minutes filing a formal complaint.
If you’ve ever wondered why a relatively small change can feel disproportionately disruptive, there may be more happening than simply being someone who “likes things a certain way.”
Changing plans requires something called cognitive flexibility—and your brain may be doing considerably more work than you realize.
What Is Cognitive Flexibility?
Cognitive flexibility is generally described as the ability to disengage from one task, rule, idea, or course of action and shift to another when circumstances change. Researchers consider it an important part of cognitive control and executive functioning.
That sounds straightforward.
Plan A isn’t going to work. Switch to Plan B.
But your brain doesn’t have a little toggle switch labeled PLAN B.
To change course, it may need to stop what it was preparing to do, disengage attention from the original plan, recognize what has changed, update relevant information, suppress responses that no longer apply, retrieve or create a new plan, shift attention toward it, and begin acting on it.
Meanwhile, you may also be managing the emotional response to the fact that this wasn’t what was supposed to happen.
That’s quite a bit of work for:
“The restaurant is closed. Let’s go somewhere else.”
Your Brain Has to Let Go Before It Can Switch
One of the most important things to understand about cognitive flexibility is that changing direction isn’t only about starting something new.
First, your brain has to stop doing—or preparing to do—the old thing.
Researchers studying task switching consistently find a switch cost: people generally respond more slowly and/or make more errors when they have to switch tasks than when they continue doing the same one. In other words, even in people without a neurological or developmental condition, switching carries a cognitive cost.
Imagine you’ve spent the morning preparing for an important 2:00 meeting.
Your notes are ready.
You’ve organized what you want to say.
You’ve structured your morning so you’ll finish another project by 1:30.
At 11:47, an email arrives:
Meeting moved to 12:00.
Technically, that’s only a calendar change.
Cognitively?
Your brain may suddenly have to stop the current task, preserve where you were in it, retrieve everything needed for the meeting, abandon the sequence you’d been following, reorganize your priorities, transition into a completely different mental context, and prepare to perform.
That’s why “It’s no big deal. Just switch gears.” can be surprisingly unhelpful advice.
Switching gears is the task.
Why Can I Handle Some Changes but Not Others?
This is where cognitive flexibility becomes particularly interesting.
You probably aren’t equally flexible all the time.
Research increasingly suggests that cognitive flexibility is context-sensitive rather than a fixed personal trait. The brain adjusts its readiness to maintain focus or switch based partly on circumstances and learned expectations.
You may handle a spontaneous lunch invitation beautifully on Saturday afternoon.
But change your plans at 4:45 on a Tuesday after eight hours of meetings, emails, interruptions, decisions, and sensory input?
Entirely different story.
That’s because flexibility doesn’t operate in isolation.
It has to share resources with everything else your brain is doing.
Cognitive Flexibility Doesn’t Work Alone
Suppose you’re cooking dinner and discover you’re missing an ingredient.
Easy enough. Substitute something else.
Except you’re also answering a work message.
Your child is asking a question.
The television is on.
You’re trying to remember whether tomorrow’s appointment is at 8:00 or 8:30.
And now the recipe isn’t going according to plan.
The ingredient may not be the real problem.
The change may simply be one more demand on a system that’s already carrying a lot.
Cognitive flexibility interacts with other processes such as attention, working memory, inhibition, planning, and cognitive control. Research into executive functioning treats these abilities as related but distinguishable processes rather than one single “executive function” switch in the brain.
That’s why the same person can sometimes pivot effortlessly and at other times feel completely derailed.
The Hidden Work Behind “Just Go With the Flow”
Think about what can happen when a plan suddenly changes.
Your brain may need to:
Disengage — Let go of what you were doing or expecting.
Inhibit — Stop the response or action you had already prepared.
Update — Replace old information with new information.
Reprioritize — Decide what matters now.
Shift attention — Move your focus toward the new task or situation.
Reorganize — Create a new sequence or plan.
Regulate — Manage frustration, disappointment, anxiety, or uncertainty.
Restart — Initiate action under the new plan.
When all of that happens efficiently, it feels like:
“Okay. Change of plans.”
When one or more parts require additional effort, it can feel more like:
“Wait. Wait. Wait. What are we doing now?”
The visible reaction may last 30 seconds.
The cognitive transition may take considerably longer.
Why Does My Brain Want to Finish the Original Plan?
Because maintaining a plan is useful.
A brain that abandoned its current goal every time something new appeared wouldn’t be particularly effective either.
Researchers describe an important balance between cognitive stability and cognitive flexibility. Stability helps us maintain attention and protect a goal from distraction. Flexibility helps us abandon or modify that goal when circumstances make another course of action more appropriate.
Both are valuable.
Too little stability and you’re constantly pulled away from what you’re doing.
Too little flexibility and changing direction becomes difficult.
So the goal isn’t:
BE FLEXIBLE ALL THE TIME.
Sometimes staying focused despite interruption is exactly what your brain should do.
The challenge is being able to determine when to stay the course and when to shift.
What Does ADHD Have to Do With Cognitive Flexibility?
For some adults with ADHD, changing tasks or reorganizing plans can be particularly difficult.
Research on adult ADHD has found differences across several aspects of executive functioning and cognitive control, including task switching and set shifting. A meta-analysis found a moderate group difference in set shifting, while other studies have reported differences in task preparation, response consistency, and task-set coordination.
But there’s an important qualification.
ADHD does not mean “inflexible brain.”
Findings vary depending on the task and how flexibility is measured. One more recent study, for example, found adults with ADHD performed better than controls on certain switching measures despite showing different patterns of brain activation.
That variability matters.
The real-life problem may not simply be whether you can switch.
It may involve when you’re asked to switch, how much preparation you have, whether the new task is interesting, what you’re already holding in working memory, how many competing demands are present, and how easily you can re-engage afterward.
An adult with ADHD might spontaneously abandon Plan A for an exciting Plan B without blinking…
…and then become completely derailed when someone else changes Plan A unexpectedly.
Human brains are inconveniently complicated that way.
What About Autism and Changes in Routine?
Difficulty with unexpected change is also commonly associated with autism, but here too we want to avoid turning a broad spectrum into a stereotype.
A 2024 meta-analysis involving 59 studies, 2,122 autistic people without intellectual disability, and 2,036 neurotypical controls found greater cognitive-flexibility difficulties in the autistic group overall, with a small-to-moderate effect—but also substantial variation among individuals and across the ways flexibility was measured.
A broader review of executive functioning in autistic adults similarly found challenges in areas including cognitive flexibility and working memory, while also identifying strengths in some executive-function domains and considerable variability between studies and individuals.
That last part is important.
Autistic people aren’t universally inflexible.
Someone may be wonderfully creative, solve problems in unconventional ways, and adapt brilliantly in one environment while finding an unexpected schedule change extremely disruptive in another.
Those things aren’t contradictory.
What About Anxiety?
Anxiety can add another layer.
Predictability reduces uncertainty.
A plan gives the brain information about what happens next. When the plan changes unexpectedly, some of that certainty disappears.
For someone whose brain is already monitoring closely for uncertainty, mistakes, potential problems, or things that might go wrong, an unexpected change may therefore create more than a logistical inconvenience.
Now there are unanswered questions.
What happens instead?
Am I prepared?
Did I forget something?
What else is going to change?
Can I handle the new situation?
The emotional response and the cognitive-switching demand can then arrive at the same time.
That doesn’t mean every person who dislikes changing plans has anxiety—or ADHD or autism.
Sometimes changing plans is simply annoying.
The question, as usual, is the pattern.
Why Is It Worse When Someone Changes MY Plan?
Oh, this one is fun.
Imagine two scenarios.
Scenario A: At 3:00, you decide you’re tired and change your evening plans.
No problem.
Scenario B: At 3:00, someone else tells you your evening plans have changed.
Suddenly:
Absolutely not.
Why?
Part of the difference may be preparation and control.
When you initiate the change, your brain is already participating in creating Plan B. The transition isn’t necessarily arriving as an external surprise.
When someone else changes the plan, your brain may have to respond after it has already invested cognitive resources in the original one.
This doesn’t automatically mean you’re controlling or unreasonable.
Sometimes it simply means:
Your brain transitions more easily when it gets to see the transition coming.
Why Can Small Changes Feel Bigger at the End of the Day?
Think back to our earlier discussion of executive-function exhaustion.
Your brain has been switching, inhibiting, remembering, prioritizing, filtering distractions, making decisions, and regulating responses all day.
Then at 6:15 someone says:
“Actually, we’re going somewhere else for dinner.”
And somehow this perfectly reasonable suggestion feels like an international incident.
The size of the change hasn’t increased.
The resources available to deal with it may have decreased.
That’s one reason context matters so much.
A change you handle easily when rested may feel dramatically different when you’re tired, hungry, overstimulated, rushed, emotionally taxed, or already juggling multiple demands.
Sometimes:
“I can’t deal with one more thing.”
is surprisingly literal.
Preparation Can Change the Cost of Switching
There’s another interesting clue in the research: preparation matters.
Task-switching studies show that advance information and preparation can reduce some of the cost associated with changing tasks, although they don’t necessarily eliminate it completely. Research in adults with ADHD has also found that some task-switching differences depend partly on how much preparation time is available.
That gives us something useful for everyday life.
Compare:
“We’re leaving NOW.”
with:
“Plans changed. We’re going to leave in 20 minutes instead of an hour.”
The outcome may be identical.
The cognitive experience isn’t.
A little warning can give the brain time to release one plan and construct another.
Can Cognitive Flexibility Improve?
Cognitive flexibility isn’t necessarily fixed.
Researchers describe flexibility as adaptive and sensitive to learning, experience, context, and practice. Experimental research has also found that targeted attention-switching practice can improve performance on switching tasks, including in adults with ADHD—although improvement on laboratory tasks should not be interpreted as proof that any particular training program will automatically produce broad everyday changes.
That distinction is important.
Neuroplasticity gives the brain the capacity to learn and adapt. It doesn’t guarantee that every exercise produces every desired outcome.
But it does give us a reason to ask whether skills involved in adapting, switching, regulating, and reorganizing can be practiced and strengthened rather than treated simply as fixed personality traits.
What Can I Do When Plans Change?
Understanding what’s happening doesn’t mean life will stop changing plans.
Unfortunately, the rest of humanity has declined to coordinate its schedule with yours.
But you can reduce some of the unnecessary cognitive load.
When possible, give yourself a moment to close Plan A before demanding Plan B. Write down where you stopped. Identify what actually changed and what stayed the same. Decide on the next action rather than rebuilding the entire day at once.
If you’re changing someone else’s plans, advance warning can help too. Instead of:
“We’re doing something different.”
try:
“The original plan changed. Here’s what’s staying the same, here’s what’s different, and here’s what happens next.”
That’s not coddling.
It’s information.
And information can make transitions easier.
When Is Difficulty With Change Worth Looking Into?
Being irritated because your flight was canceled doesn’t mean you have an executive-function problem.
Neither does preferring routines.
But it may be worth looking more closely when difficulty adapting to changes is frequent, intense, or consistently interferes with work, relationships, responsibilities, or everyday life.
You might notice that:
You need unusually long periods to recover after interruptions.
Small changes routinely derail the rest of your day.
Switching tasks feels disproportionately exhausting.
You become intensely frustrated or anxious when plans change.
You lose track of the original task after an interruption.
You avoid situations primarily because you cannot predict what will happen.
Or people frequently describe you as rigid when, internally, the experience feels more like overload.
Those patterns can tell us considerably more than one bad reaction to one changed dinner reservation.
What NeuroFiT Looks At
At NeuroFiT Connections, we don’t assume that difficulty with change comes from one particular diagnosis—or even one particular cognitive skill.
Our Adult Brain & Body Assessment looks across multiple areas of function, including cognitive and executive skills, visual and oculomotor function, auditory processing, fine motor skills, balance and postural control, coordination and motor planning, timing and rhythm, proprioception and body awareness, primitive reflexes, and the everyday challenges and goals that matter to you.
Why look so broadly?
Because everyday functioning rarely depends on one system operating alone.
What feels like “I can’t handle changes” might involve a combination of attention shifting, working memory, task initiation, sensory load, regulation, planning, timing, or other functional demands.
We don’t build programs around diagnoses. We build them around people.
Maybe You’re Not “Bad at Going With the Flow”
Perhaps you’ve spent years describing yourself as:
Rigid.
Controlling.
Particular.
Easily irritated.
Bad with change.
Maybe those descriptions contain some truth.
But they don’t tell us very much about why.
The next time a changed plan creates a surprisingly strong reaction, instead of immediately asking:
“Why am I making such a big deal about this?”
try asking:
“What did my brain just have to reorganize?”
You may discover that the problem wasn’t simply the change.
It was everything required to make the change.
Frequently Asked Questions About Cognitive Flexibility in Adults
What is cognitive flexibility?
Cognitive flexibility is the ability to disengage from one task, rule, strategy, or mental set and shift toward another when circumstances change. It is generally considered an important component of cognitive control and executive functioning.
Is difficulty with changes in plans a sign of ADHD?
It can occur in adults with ADHD, particularly alongside difficulties involving executive function, task switching, attention, working memory, or regulation. But difficulty with change alone does not indicate ADHD, and research findings on cognitive flexibility in ADHD vary depending on how it is measured.
Is difficulty with change a sign of autism?
Difficulty adapting to change can occur in autistic people, and research has found group-level differences in cognitive flexibility. However, autism is highly variable, and difficulty with change by itself cannot diagnose autism.
Why do I handle changes better when I make them myself?
Self-initiated changes can provide more preparation and a greater sense of predictability. When a change comes unexpectedly from someone else, your brain may have to disengage from an already-established plan and reorganize without advance preparation.
Why are changes harder when I’m tired?
Cognitive flexibility interacts with other executive and cognitive demands. When you’re already tired, overstimulated, stressed, or managing multiple tasks, there may be fewer resources available for stopping, updating, reorganizing, and restarting.
Is cognitive flexibility the same as multitasking?
No. They’re related but not identical. Cognitive flexibility involves shifting between mental sets, tasks, or strategies, while multitasking may involve managing multiple competing tasks or goals. Research suggests both place demands on cognitive control.
Can cognitive flexibility be improved?
Research suggests cognitive flexibility can adapt with learning, context, and practice, and experimental studies have demonstrated improvement on attention-switching tasks. How well those improvements generalize to everyday life depends on the individual and the type of training.
Does NeuroFiT Connections diagnose ADHD, autism, or anxiety?
No. NeuroFiT Connections’ Brain & Body Assessment is designed to identify individual patterns of strengths and functional challenges. Medical and psychological diagnoses should be made by appropriately qualified professionals.
Do I need a diagnosis to have a Brain & Body Assessment?
No. You may simply recognize that certain aspects of everyday life—such as attention, organization, transitions, sensory processing, coordination, or regulation—require more effort than you think they should.
What is the first step?
The first step is a personalized Adult Brain & Body Assessment. It helps us understand your individual pattern of strengths and challenges before determining whether a personalized Brain & Body Training program may be appropriate.
Ready to Better Understand Your Brain & Body?
If changes, interruptions, transitions, or unexpected demands seem to throw you off more than they should, there may be more worth understanding.
