There's a Kiwi reggae band called Fat Freddy's Drop, and I got the mp3s of their first album Based on a True Story from a friend not too long after it came out. Later I lost them on an old HD, and when I went to get the album again most of the songs were different versions, and noticeably worse than what I remember. I've been able to track down a few of the old versions over the years but not all of them.
Part of the difficulty is not knowing what the versions I first heard were. They didn't sound live so it's not as simple as trying to find concert versions. Trying to find a specific version of a song can be more frustrating than not knowing what a song is entirely :/