One Learning Habit I’m Trying to Break

The Illusion of Competence

One idea from A Mind for Numbers by Barbara Oakley has stayed with me because it perfectly describes a trap I’ve fallen into more than once: the illusion of competence.

It’s surprisingly easy to mistake familiarity for understanding.

I’ve experienced it many times. I finish reading a chapter, follow a lecture, or work through a beautifully explained derivation and think, “That makes perfect sense.” But when I close the book and try to solve a similar problem on my own, I realize I don’t actually know where to begin.

That moment is humbling—but it’s also incredibly valuable.

I’ve learned that recognizing an idea is not the same as understanding it. Real learning begins only when I can explain a concept without looking at my notes, derive an equation from first principles, or apply the idea to a completely new problem. As a computational geodynamics researcher, this often happens when I move from reading a paper to implementing the method in code. That’s when the gaps in my understanding become obvious—and that’s where the real learning starts.

So I’ve been trying to change the way I study.

Instead of rereading the same pages, I close the book and ask myself:

• Can I explain this in my own words?
• Can I solve a similar problem without looking at the solution?
• Could I teach this concept to someone else?
• Do I understand why it works, not just how it works?

When the answer is “not yet,” I don’t see it as failure anymore. It’s simply a signal that my brain is still building the connections.

A few habits have helped me avoid this illusion:

• I practice active recall instead of endlessly rereading.
• I solve new problems rather than repeating familiar examples.
• I revisit topics after a few days to test whether the ideas have truly stuck.
• I try to embrace the struggle instead of rushing to the solution. Some of my biggest “aha!” moments have come after sitting with a difficult problem longer than I wanted to.

One of the biggest lessons I’ve learned is that learning rarely feels comfortable. In fact, the moments when I feel confused are often the moments when my understanding is about to deepen.

So now, whenever I catch myself thinking, “I know this,” I ask a better question:

“Can I still do it when the book is closed?”

That’s the test I trust.

And perhaps that’s what real learning is all about—not collecting information, but building understanding that stays with us long after we’ve closed the book.