I think it's the same way with science. The material we cover in lectures can't be understood by just taking notes, no matter how thorough the notes or how carefully students have been listening. And coming back to those notes a few days before the exam is never adequate. By then the story line has gone in so many directions it's hard to get a handle on exactly what transpired during all those weeks.
I ask my students, urge them in fact, to re-read their notes at the end of the day they wrote them. Every day we have lecture I want my students to go back to their notes, starting with the first lecture, and review what they've written all the way up to the most recent lecture. This shouldn't take more than fifteen minutes or so.
During lecture I ask my students to sketch, draw arrows to things that are connected, circle important phrases, and sometimes, to put questions I interject in parentheses after a statement. All of these are mnemonic devices to encourage deep understanding of the material. But no matter how fresh and agile their brains, if students come back to these notes too long after they've written them, the signal is weakened. It's too hard to pick up the scent of a concept.
It's kind of nerdy to study this way. I know I never managed to do it. But I didn't care as much about my grades as these students do. So when I see my students in lecture today I'll ask them, "What study technique did I mention during the last lecture?" They'll probably answer, "contemplation?" "analysis?" "observation?". Nice sounding answers and all part of learning. But if they had re-read their notes from last time they'd know. Study it twice to learn it better.