What Do You Do With Your Notes?

Moleskin comet: "I actually don't use moleskins because i don't like the paper. It's too thin" I have a whole shelf full of notebooks that look just like this one, going back many, many years. But some people work better with sticky notes or with loose sheets of paper,. They question i always have, actually, in either case, is, what next? So you take notes, right? Let's say that you're in a lecture or reading a book, and you're putting down ideas. Do you ever revisit those pieces of paper? What do you do with those notes?