I've been trying to look back through 2008. I've been keeping this journal (fine, "diary") so I can remember what I did everyday. And sometimes, when I'm extra reflective, I leave small notes for my future self. Small notes and lessons that I should remember from what happened that particular day (e.g. "don't allow anger to consume you, PRAY!", "It's hard to expect for things that never come", etc)
I must say... I keep on repeating the same mistakes over and over again. Maybe this can be a good new year's resolution.