Do you know how a zipper works?
Weird question from a physiotherapist, right?
Well, hear me out.
In a series of studies, Yale researchers asked participants to rate how well they understood everyday devices on a scale from 1 to 7.
Zippers. Flush toilets. Sewing machines. Piano keys.
Nothing particularly exotic.
Then came the uncomfortable part: participants had to write a detailed, step-by-step explanation of how selected devices actually worked.
Afterward, they rated their understanding again.
Their confidence dropped.
Apparently, “Of course I know how that works” gets a little shaky when someone hands you a blank sheet of paper.
The researchers called this the illusion of explanatory depth: we think we understand how something works more deeply than we actually do.
In their studies, this gap was greater for explanations of how things work than for recalling facts or describing procedures. Knowing what something does can give us the impression that we also understand how it does it.
Now, what does this have to do with physiotherapy?
The study wasn’t about exercise motivation. But it made me think about the explanations we give for our own behavior.
When I ask patients what keeps them from exercising regularly, a common answer is:
“I don’t have enough time.”
Fair enough.
But what does that actually mean?
Is the day genuinely full?
Does exercise mean an hour at the gym, plus driving there, changing, showering, and driving home?
Is there some time available, but absolutely no energy left?
Or does the whole thing feel so unpleasant that finding time for it never gets very far up the list?
Those are different problems. Yet all of them can fit comfortably inside the same sentence.
“I don’t have time.”
Sometimes that sentence is entirely accurate. Sometimes it’s the beginning of an explanation we’ve never finished.
And when we try to finish it, things can get uncomfortable.
An answer that felt obvious suddenly needs more detail.
That doesn’t automatically mean we were making excuses. It might simply mean we hadn’t looked closely enough to know what was actually getting in the way.
How do you change a pattern you’ve only explained with a label?
If time really is the problem, we need to look at the schedule.
If the plan demands more energy than we have, squeezing it into an already exhausting evening probably won’t help.
If we think only a full workout counts, we might be overlooking smaller options before we even consider them.
The details matter.
And this goes beyond exercise.
“I work hard because I want to earn more money.”
Okay. What would more money give you?
Security? Independence? More choices?
Or have you been following a definition of success that you picked up somewhere along the way?
We absorb ideas from our families, workplaces, and the culture around us. Repeat them often enough, and they can start to feel like conclusions we reached ourselves.
Everybody is too busy to exercise, right?
Everybody wants to earn more money, right?
There’s always a familiar answer available. Whether it explains your life is another question.
Richard Feynman put it bluntly:
The first principle is that you must not fool yourself and you are the easiest person to fool.
That includes me.
Being able to question someone else’s explanation doesn’t make my own explanations automatically correct.
I can know my routines by heart and still misunderstand what keeps them going. I can repeat a goal for years without asking whether I still want what it promises.
Familiarity makes it easy to stop asking questions.
But being familiar with something doesn’t mean you understand it.
Think about the zipper again.
You’ve used one thousands of times.
You know what happens when you pull it.
Could you explain what happens between the teeth?
🧪 Let’s Experiment
You can know an answer by heart without understanding it.
You probably already have an explanation for that thing you keep doing—or keep avoiding.
Let’s see how much it actually explains.
🎯 Try This:
Choose one familiar answer:
“I don’t have time.”
“I’m just not motivated.”
“That’s simply how I am.”
Now spend five minutes explaining what it means in one recent situation.
If you write “I don’t have time,” describe what filled the time. What were you planning to do? What happened instead?
If you write “I wasn’t motivated,” describe what that looked like. What does that mean to you? What were you doing instead?
If you write “That’s just how I am,” describe what you actually did. Where does it come from? How did one lead to the other?
Wherever you get stuck, write a question instead of forcing an answer.
What part of this do I still not understand?
🧠 Final Thought:
The zipper looked pretty straightforward too.
Until someone asked you to explain it.