I used to think this way, but I had one too many things I acquired, then deleted because I wasn't really listening to it, then years later suddenly wanting to try it again because something just clicked and spending many, many hours having to re-acquire it.
Storage is cheap. I just keep everything and buy a bigger hard-drive.
Most of my headaches these days are around whether I correctly tagged something the first go-round and now having to sync all my backups when I decide I want to reorganize some of my albums.