Why Knowing What to Do Doesn't Always Mean Being Able to Do It
There are some tasks you don’t do because you don’t know how. Then there are the ones that are much harder to explain.
You know the email needs a reply and you already have a reasonable idea of what you want to say. You know the washing needs to come out of the machine, the form needs to be submitted, or that if you start getting ready now you’ll have plenty of time.
None of this information is missing. Yet knowing what needs to happen doesn’t always translate neatly into doing it.
You may carry a task around in your mind for much longer than the task itself would take, repeatedly thinking I need to do that without quite moving towards it. Perhaps you begin and get pulled into something else, only to realise later that the original task is still unfinished.
When this happens often enough, it’s easy to assume the problem must lie in your attitude towards the task. Perhaps you don’t care enough, you aren’t disciplined enough, or you simply need to try harder. Sometimes motivation or avoidance may well be part of what is happening, but they aren’t the only possibilities.
Knowing what to do and organising yourself to do it aren’t the same cognitive process.
An intention still has to become an action
We tend to compress everyday tasks when we think about them.
Send the email. Make the appointment. Pay the bill. Get ready.
Each sounds like a single action, but there is quite a lot happening between deciding to do something and actually completing it. The intention needs to remain available while you disengage from whatever you’re already doing, direct your attention towards the new task and begin. If there are several steps, you need to work your way through them, resist or recover from distractions and notice if you’ve drifted away from what you intended to do. If something changes halfway through, you may need to adjust the plan as you go.
Most of the time, we don’t experience these as separate mental processes. We simply experience ourselves getting something done, which makes it difficult to understand what is happening when that apparently seamless sequence repeatedly breaks down.
You may know exactly what needs to happen. The difficulty can arise somewhere between forming the intention and carrying it through.
Executive functions help us act on what we know
This is one place where executive functioning can be useful for understanding ADHD.
Executive functions are a group of mental processes involved in regulating goal-directed behaviour. They help us hold information in mind, inhibit immediate responses, shift attention, organise and sequence actions, monitor what we’re doing and keep our behaviour connected to an intended outcome.
ADHD isn’t simply an executive-function disorder, and executive difficulties aren’t unique to ADHD. However, differences in executive functioning are commonly associated with the condition and can help explain experiences that make much less sense if we look only at what somebody knows or how motivated they appear to be.
It is entirely possible to understand that something matters, genuinely intend to do it and still have difficulty organising your behaviour around that understanding. In everyday life, recognising that distinction can change the meaning of a great deal.
Starting is its own part of the process
Consider a task you’ve been putting off. From the outside, there seem to be only two possibilities: you’re doing it or you aren’t.
Beginning, though, requires a transition. You have to move away from whatever is occupying you now and towards something you aren’t yet doing. Sometimes that shift happens almost effortlessly. You think I’ll do that now, and you do.
At other times, the distance between deciding and starting can feel surprisingly large. You open the document but check something else first. You decide you’ll begin after making coffee. You think about the task repeatedly while continuing to do other things, with the unfinished task becoming increasingly uncomfortable in the background.
What makes this especially confusing is that you may not be consciously choosing not to do it. You want it finished, and the fact that it remains unfinished may be causing considerable stress. Yet wanting to begin and actually crossing into the task still seem strangely disconnected.
Difficulty with task initiation is one of the executive-function experiences often discussed in relation to ADHD. This doesn’t mean that every reluctance to start an unpleasant task is an executive-function problem. Nobody approaches every responsibility enthusiastically. What becomes more interesting is the repeated pattern in which the intention is genuinely present, but action doesn’t follow as readily as you expect.
A task can be simple and still be difficult to enter
One of the more frustrating aspects of this experience is that the difficulty of starting something doesn’t always correspond with how objectively difficult the task appears to be.
You may complete highly complex work and then avoid making a straightforward phone call. Perhaps you can manage a demanding project involving dozens of moving parts, yet spend several days thinking about a form that would probably take five minutes to complete.
That inconsistency can make the problem feel particularly personal. I’ve done much harder things than this. Why can’t I just do it?
But tasks can be demanding in different ways. A complex project may be interesting, clearly structured or connected to other people. It may provide deadlines, feedback and obvious next steps. A five-minute administrative task can be vague, repetitive and easy to postpone. You may need to stop what you’re doing, locate some information, make a decision and remember to return to it if you’re interrupted.
Its intellectual difficulty may be low while its executive demands are not.
Sometimes “I can’t start” means “I can’t find the first step”
A task can also look much clearer from a distance than it feels when you actually approach it.
Take sort out the insurance. You know roughly what the finished outcome should be, but once you sit down, the task begins to expand. Do you need to find the policy first? Compare something? Log into an account? Where is the password? Is there information you need before you can make a decision? Do you need to call somebody?
What looked like one task has quietly become a series of smaller tasks and decisions, and the first one may not be obvious.
The same thing can happen with broad instructions such as clean the house, update my résumé, plan the trip or do my tax. Each contains multiple actions that need to be identified, ordered and carried through. If the entry point remains unclear, you can spend a surprising amount of time circling the task without finding your way into it.
What looks from the outside like a failure to begin may sometimes be difficulty turning a broad intention into a sufficiently clear next action.
Knowing something is important doesn’t guarantee access to action
We often assume that importance should be enough to get us moving. Sometimes it is. Yet many people exploring ADHD describe becoming stuck on tasks that matter enormously to them.
The bill matters because it’s overdue. The application matters because you desperately want the opportunity. The message matters because you care about the person waiting for a reply. In situations like these, knowing how much the task matters can make the inability to act more distressing rather than less.
You may keep reminding yourself of the consequences in the hope that making the task feel more important will finally get you moving. Then the deadline gets closer, somebody follows up or the consequences become immediate, and suddenly the task that felt inaccessible becomes possible.
It can seem as though you finally cared enough to do it. But another possibility is that something changed in the conditions under which your attention and action were being organised.
Urgency can close the gap
If you regularly get things done at the last minute, you may have concluded that you simply work better under pressure. There can be some truth in that observation, although it doesn’t necessarily mean pressure brings out some hidden preference for chaos.
A distant task has to compete with everything happening now. As the deadline approaches, the task itself becomes part of what is happening now. The options narrow, the consequences become more concrete and there is less room for repeatedly deciding whether this is the right moment to begin.
For some people with ADHD, those conditions can make engagement considerably easier. A task that remained untouched for three weeks may suddenly become the sole focus of attention when only six hours remain.
Your ability to do the work didn’t suddenly appear. You knew how to do it all along. What changed was the context in which you were trying to access that ability.
Of course, this doesn’t make last-minute pressure a harmless or particularly sustainable way to function. Repeated urgency can bring stress, lost sleep and the disruption of everything else that has to be pushed aside. What it can do is offer useful information about why the task may have been difficult to access earlier.
Other people can sometimes make starting easier
You may also notice that something becomes easier to begin when another person enters the picture.
Paperwork you’ve avoided for weeks suddenly becomes manageable when somebody sits beside you. A stalled piece of work moves when a colleague asks where it’s up to. You clean more easily when someone is coming over, or finally make the phone call after telling another person you’ll do it.
It can be tempting to see this as proof that you could have done the task earlier if you had really wanted to. Yet another person’s presence can change the task environment in ways that have little to do with how much you care.
There may now be a clearer starting point, immediate feedback, a stronger sense of time or simply less opportunity for the task to compete privately with everything else demanding your attention. The thing you need to do hasn’t changed, and neither has your knowledge of how to do it. The conditions surrounding action have.
The same person can look highly capable in one setting and stuck in another
This dependence on context is one reason ADHD-related difficulties can look so inconsistent.
Someone may function extremely well at work, where there are meetings, deadlines, colleagues and clearly defined responsibilities, then arrive home and spend three weeks unable to book a dentist appointment. Another person may manage their own routines relatively well but struggle considerably in a workplace filled with interruptions and competing priorities.
Neither situation tells us what that person is capable of under every set of circumstances.
Structure, interest, urgency, novelty, clarity and external support can all influence how easily someone moves from knowing to doing. Looking only at the situations in which a person functions well can therefore give us an incomplete picture.
A more useful question is not simply whether someone can do something, but how reliably they can access that ability across the different situations in which they need it.
Repeated difficulty can change the way you understand yourself
When the gap between intention and action keeps appearing, it rarely remains a neutral observation.
You said you would do something and didn’t. You left another task until the last minute. You forgot the thing you had specifically told yourself not to forget. Each outcome becomes another piece of evidence, and without another way of understanding the pattern, the explanation can gradually become personal.
I’m lazy. I’m unreliable. I have no self-discipline.
Those conclusions can feel convincing precisely because they’re built around things that really happened. The task wasn’t done. The deadline was missed. Somebody was inconvenienced.
Understanding executive functioning doesn’t require pretending those outcomes don’t matter. It simply allows us to separate the outcome from the assumptions we make about the process that produced it.
That opens up a different kind of question. Instead of asking what an unfinished task proves about your character, you can begin to look at where the process became difficult.
Understanding a difficulty doesn’t remove responsibility
That distinction matters because explanation and responsibility aren’t opposites.
Forgetting to pay a bill can still have consequences. Not replying to someone can still affect them. Missing a deadline can still create additional work for somebody else. ADHD doesn’t make any of those consequences disappear.
What understanding can change is the accuracy of your response to the problem.
If every unfinished task is assumed to be the result of insufficient effort, then demanding more effort seems like the obvious solution. Sometimes that may help. But if the recurring difficulty lies in remembering the intention, identifying a starting point, shifting attention or organising several steps, simply trying harder may leave the actual problem untouched.
Taking responsibility can include understanding where the process tends to break down and finding ways to support it more effectively. That is very different from deciding that blame is the only thing likely to produce change.
This experience isn’t specific to ADHD
Almost everyone has things they know they should do and don’t. We procrastinate, avoid tasks that feel unpleasant or uncertain, and find it harder to begin when we’re exhausted, stressed or overwhelmed. Anxiety, depression and many other factors can also affect our ability to initiate and complete tasks.
So recognising a gap between knowing and doing doesn’t mean you have ADHD.
When ADHD is being considered, clinicians look at the broader developmental picture: the nature and persistence of relevant symptoms, how they appear across different settings, their impact on functioning and whether another explanation better accounts for what is happening.
If ADHD is something you’re exploring, noticing the pattern can still be useful without treating individual experiences as proof. You might begin to notice when action comes relatively easily and when the gap becomes larger. Perhaps urgency changes something, or another person’s involvement helps. Maybe clearly structured tasks are easier to enter than open-ended ones, or you recognise versions of the same difficulty stretching back across different periods of your life.
Those observations can tell you much more about your experience than simply concluding, I procrastinate.
The difficulty may be in the space between
It’s easy to imagine that once we know what to do, action should follow naturally. Often it does, which is probably why we pay so little attention to everything that happens in between.
We notice the appointment that wasn’t made, not the sequence required for I should make an appointment to become I’ve made it. We see the unfinished task rather than the repeated attempts to bring attention towards it. We see someone suddenly working with intense focus as a deadline approaches and wonder why they couldn’t simply have done the same thing three weeks earlier.
The processes connecting intention with action are mostly invisible until something interrupts them.
Sometimes, then, the most useful question isn’t whether someone knew what to do. They probably did.
It is what happened in the space between knowing and doing.
A moment to wonder
Think about something you often know you need to do but find unexpectedly difficult to carry through.
Where does the process tend to become harder? It might be beginning, deciding where to start, keeping the intention in mind, returning after an interruption or moving away from something else first. You might also notice the situations in which the same kind of task becomes easier.
You don’t need to explain the pattern or decide whether ADHD is responsible for it. For now, simply notice the difference between knowing what needs to happen and the process of making it happen.
Keep exploring
There’s more to explore across Through the Disconnect, from understanding ADHD and life after diagnosis to masking and making sense of your experience.
References
Alderson, R. M., Kasper, L. J., Hudec, K. L., & Patros, C. H. G. (2013). Attention-deficit/hyperactivity disorder (ADHD) and working memory in adults: A meta-analytic review. Neuropsychology, 27(3), 287–302.
American Psychiatric Association. (2022). Diagnostic and statistical manual of mental disorders (5th ed., text rev.; DSM-5-TR). American Psychiatric Association Publishing.
Australian ADHD Professionals Association. (2022). Australian evidence-based clinical practice guideline for attention deficit hyperactivity disorder (ADHD).
Boonstra, A. M., Oosterlaan, J., Sergeant, J. A., & Buitelaar, J. K. (2005). Executive functioning in adult ADHD: A meta-analytic review. Psychological Medicine, 35(8), 1097–1108.
Cortese, S., et al. (2025). Attention-deficit/hyperactivity disorder (ADHD) in adults: Evidence base, uncertainties and controversies. World Psychiatry.
Willcutt, E. G., Doyle, A. E., Nigg, J. T., Faraone, S. V., & Pennington, B. F. (2005). Validity of the executive function theory of attention-deficit/hyperactivity disorder: A meta-analytic review. Biological Psychiatry, 57(11), 1336–1346.
