I have my work notes, but reading this makes me think I should really take up a personal journal. Occasionally I find that there's past memories and experiences where the specifics get kinda washed-out if I don't actively revisit them. I make a mental note to recall really nice experiences, and sometimes certain moods and moments get translated into artistic interpretations, but maybe I should keep a more prescribed record. I especially think I want to do this when I visit Japan in a few months.
I recently dug up my Evernote account, where I promptly realized that I had kept a diary for the first 18 months of college. There is a lot of menial stuff but I absolutely love reading it back. Life doesn't need to be special for a journal to matter, although it does help. :)