Joan Didion writes, in On Keeping a Notebook, that the purpose of keeping a notebook, or a journal for that matter, isn’t because you simply want keep a personal record of things; but because you want to remember the person you were at that specific moment. we write things down on our notebook/journal/diary (whichever one of those you keep) because we want to remember. we want to remember what specific people meant to us on a particular day or hour. or minute. we want to remember our first impression of something (or of doing that something), possibly of someone, too. sometimes we think we’ll “always remember” important events: “I’ll make a mental note of that” etc etc. but in reality everything is fleeting. so Didion says write it down. keep a journal. that way, people, places, and certain events will always be there in case you ever want to come back to them sometime in the future. but also so that they don’t ever haunt you.