You heard of memory maps? I think that's what they are called (hedging my bets with 'mind map', might be that too)..
I wish I could create one. Just *one*. With everything that I've seen. In one place. Forever.
If I had a coupl'a million to burn, I'd build a room, with a massive 10m x 2m monitor (or something equally impressive, and 'wall size') and invest in some custom software for mapping out everything that I know. Then I could walk over to my wall, and look for stuff.
That'd be awesome.