Highlighting a paragraph a second time creates a comfortable illusion of learning: the material looks familiar, so it feels known. Whether you can actually produce the answer without the page in front of you is a different question entirely.
Recognition isn't recall
Multiple-choice familiarity can mask a real gap, because picking the right answer out of four options is easier than generating it from scratch. Practice questions force the harder version of the task, which is closer to what the actual exam demands.
Make the retrieval effortful on purpose
Testing yourself before you feel ready is uncomfortable, and that discomfort is doing the work. Waiting until material feels fully mastered before testing it usually just means you've delayed the part where real learning happens.
Space it, don't cram it
A single successful recall isn't durable on its own. Revisiting the same concept after a gap, right around when it starts to feel fuzzy again, is what moves it into longer-term memory.