Stop Practising the Easy Version

"I feel like I finally get it," said Teo Brisku, closing his laptop at the kitchen table after two hours of drilling the same algebra chapter. His younger sister looked up from her own work. He had done forty-seven variations of the same problem type, each one a little faster than the last. He felt genuinely good. He failed the test four days later.

Here is what happened. When you practise one problem type until it flows, you are training recognition, not thinking. Each repetition confirms what you already know rather than building anything new. Fluency is not learning — it is learning's most convincing impersonator. The smoothness you feel is real, but it is measuring how well you perform under ideal conditions. It says almost nothing about what you can do when the context shifts, the stakes are up, and the cues that told you which tool to reach for are gone.

Researchers studying motor learning and mathematics have documented this gap repeatedly. One set of studies, discussed at length in Robert Bjork's work on desirable difficulties, found that students who interleaved problem types — switching between multiplication, division, and fractions within a single session — scored consistently higher on delayed tests than students who blocked their practice, even when the blocked group felt more confident going in. Bjork's phrase for this is pointed: the conditions that make performance feel better tend to make learning worse.

If you are working through anything right now — a language, a set of financial models, a body of case law — notice when a session starts to feel frictionless. That smoothness is a signal, not a reward. Teo's mistake was treating ease as evidence of arrival. Instead, before you close the laptop, pull in one problem from an adjacent type: something that looks similar but requires a different move. The brief confusion that follows is your brain being asked to discriminate rather than just pattern-match. It is uncomfortable. It is also the thing.

You do not get better by feeling capable. You get better by being briefly, productively lost — and finding your way out without the map you used last time.