Honestly, I recommend paper. I know, I know, no full-text search, no backup, etc. But files are really easy to misplace, accidently delete, or lose due to a hardware/software failure. They're just so small.

I've found that if I write something down on paper, I'll physically remember where it is. It's really hard to get past the permanent aspect of pen and paper, but once you do, and you're willing to write down imperfect thoughts with zero organization, it's wonderful.