Something related to this that I've been thinking about. We all have kind of a story of ourselves and our life through various memories that make a picture of who we are. But if you ever meet up with someone you haven't seen for 20 years, or find some old documents, or whatever, stuff can easily come up that you've completely forgotten, or reframe things in a whole different light.

We know this kind of thing happens with history - certain people become famous while others drift into obscurity, things get remembered incorrectly etc - but it also happens with your own memory of your own life. The only real way around it is keeping a journal.