As a teenager I got wound up in the narrative of productivity, note taking, and all that. Since then, I've had to unlearn that writing (well, note-taking) just for the sake of organizing some information nobody will go back to is not the best use for my time. I've discovered that having the best notes doesn't magically make me better prepared to get something done at work. The best way to create something new is to JustDoIt tm (and fail, and do it again, ..). To me, it's important to trust your brain to do the magic. Your job is to help it do it's magic. Paper doesn't think. It may help YOU think, but IT doesn't think.
However, I'm in my 20s, and I do keep a journal and I write frequently. But I've shifted my writing from productivity to emotions. I've found that expressing my own emotions and non-productive thinking on paper helps me understand myself.