I have a lightweight version of this. I have one playlist called "Story of my life". If I have a song that is consistently stuck in my head, my go-to to kick off a listening session, or otherwise very notable, I will add it to the playlist. This results in a playlist where I have a song for each "season" of my life. I can pick out a song and will often remember what was happening in my life when I added it, and what their general feeling of the time was.

This is all separate from my ever-changing genre-specific playlists that I like to maintain and listen to.