"I Feel Like I'm Getting It" — Until the Test

Seventy-two flash cards, rubber-banded by colour, stacked in four clean piles on a kitchen table. Oksana Brevel had sorted them herself — vocabulary in one pile, grammar drills in another, listening notes in a third. She ran through the vocabulary pile twice in a single sitting and felt, genuinely and unmistakably, like she was finally getting somewhere.

That feeling was real. It was also the wrong signal. Fluency and learning feel identical from the inside, which is exactly what makes fluency so dangerous. When you block your practice — all the fractions, then all the decimals, then all the percentages. Performance climbs fast because your brain is still holding the context from the last problem. You are not retrieving a method. You are continuing it. The test removes that context. The knowledge, as it turns out, was mostly scaffolding.

Researchers studying motor and cognitive skill have documented this gap repeatedly. The most cited demonstration comes from work on interleaved versus blocked practice, replicated across domains from maths to tennis serves: learners in blocked conditions score higher at the end of practice sessions and lower on delayed tests. The groups flip almost exactly. It is uncomfortable enough that the finding has a name in the literature. The desirable difficulty effect. Credit usually given to Robert Bjork's lab at UCLA, whose work on this is well-documented and publicly available.

Say you are learning to mix and EQ audio. You have been drilling compression for forty minutes and you feel locked in. You could open a new session and keep going, consolidating the feeling. Or you could switch now to EQ, then to reverb, then back to compression, and feel the friction of not knowing immediately which tool applies. Oksana eventually broke the rubber bands and shuffled all four piles together. The sessions became harder to sit through. The quarterly assessment she took six weeks later was not.

Your brain does not learn from being right. It learns from the small, uncomfortable work of figuring out which approach even applies. The fluency was never the goal. It was always just the most convincing way to feel finished.