There’s sort of an irony in exam prep: the more you re-read your notes, the more confident you feel – but the more unprepared you actually are.

This trap has a name: the illusion of mastery. When you repeatedly go over the same notes or highlighted textbook pages, your brain recognises the information. That sense of familiarity feels reassuring – like, “Oh yes, I know this!” But this familiarity isn’t actually memory. You don’t truly know something until you can recall it without cues.

Psychologists have studied this. One famous experiment showed that students who simply re-read material felt more confident before tests but performed significantly worse than those who practiced retrieval – like testing themselves, writing summaries from memory, or explaining concepts aloud.

The problem is, our brains are wired to crave ease. Rereading feels smooth, while self-testing feels uncomfortable and difficult – you’re constantly reminded of what you don’t know. But that discomfort is exactly where learning happens.

So, what should you do instead?
– Close your notes and write everything you can remember. Then check gaps.
– Revisit topics over several days rather than cramming in one.
– Mix question types and topics

Think of re-reading like watching someone else work out – it looks productive, but you’re not building the muscle. Real learning feels effortful. Next time you catch yourself peacefully scrolling through your highlighted notes, remember: that confidence might be the biggest test illusion of all.

Oliver Fletcher