I have described my memory as a shelf of marbles. Add new ones to the edges, sometimes they fall off immediately, sometimes they push off other recently added marbles, sometimes one at the other end falls off.
A bunch of marbles that aren't particularly important but have been there a while, or got thrown on with enough force, are along the back against the wall and will seemingly stay forever. Like the lyrics to terrible songs, or unpleasant memories.
I'm always losing my marbles...
