I don't think there's any right or wrong here. Maybe some of us listen to our own music because we wrote something we love and we're proud of it. Maybe it's to listen critically to know what to do better in the future. Maybe everyone else was doing it wrong so we arranged the notes how we most like them and listen to it for that reason.
I wouldn't say you're narcissistic for listening to your own music over and over again. I'm sure painters decorate their homes with their artwork, and ex-athletes line the walls with their trophies and medals.
But me personally, I cringe at listening to my own stuff. All I can hear are the flaws, the mistakes, the wrong tones, etc. Maybe I go back to it once in a while after months or years apart from it, but rarely.
So why do I even write? lol
I guess it's something like what Picasso said: If they took away all my paints, I'd use pastels, if they took away my pastels, I'd use crayons, if they took away my crayons, I'd use a pencil. If they put me in a cell, and stripped me of everything, I'd spit on my finger and draw on the wall.