There are two very different things students do when they study: passive review and active recall. Passive review is re-reading notes, highlighting textbooks, watching the same lecture again, and looking over worked examples. It feels like studying because it requires attention and time. But it creates recognition, not recall — the dangerous sensation of knowing something you have not actually learned. Active recall is closing your notes and asking yourself: what do I actually know about this topic? Then retrieving it from memory, checking what you missed, and trying again. It is harder and less comfortable than re-reading. That discomfort is the learning happening. The research comparing these two methods is not close. Active recall outperforms passive review at every timescale and every difficulty level.