It's also a recognition that things are written in a time-frame and the context becomes increasingly distant as time passes. One may even begin to doubt if they wrote something themselves or believed it if they are shown a copy of it from 20 years ago.

Perhaps not a problem for most, but I've occasionally come across a chat transcript where I am a participant and I couldn't tell what the hell I was talking about because much of our generation's cognition is adapted to communication with humans via audible speech and tone. It might have sounded obvious then, to me and the participants but it's no longer known what the context or the beliefs were. Perhaps I'm too inconsistent and I want to mark what I don't believe as such, so that if I ever look back, I can't be convinced otherwise ?! Haha.