In my case, it's a case of keeping track of things, whether it's anewly acquired album, recently read article or recently experienced musical event. I've bought, and continue to buy, a lot of music. I need to keep track of what it was, what I thought about it and where it fits into a genre and discography.
I have a swag of magazines, bookmarked articles and such that need some sort of filing system. I figure I just might have found a way to keep trck of some of it.
Given is a fading memory. I'll review a concert while it's fresh in my mind because that's the best chance I have to remember what happened.
Simple, straightforward, and largely intended for an audience of one some time down the track when I want to revisit the experience.