Your playlist from three years ago sounds weird now. The songs didn’t change.

Music that no longer fits is a reading of you rather than of the music. Nothing about it changed, which makes it one of the few honest instruments you have for measuring internal movement, and the strangeness you feel listening back is the distance itself becoming audible.

Put on something you played constantly a few years ago and pay attention to what feels off. That reaction is data about who you have become. It is worth a few minutes of thought, and it is more reliable than asking yourself directly.