I am a wasteful note taker.
Small bits of paper, large sheets of paper. Writing scrawled on walls in sharpie, only to need me to paint over the once urgent messages when they are no longer applicable.
I write down ideas, demands, concept structures, priority lists, etc, during my brainstorming, or problem solving phases. -- I've noticed that many of these symbols and ideas are repeated over the course of time.
Eventually the useful ones are used so frequently that they tend to crystalize in the mind.
I am surprised that the act of writing them down is more vital than actually keeping the notes, or re-visiting them.