With me it's just become a habit. I might try going a few days without for a bit. Overindulgence and degradation of the senses can only be a bad thing. Music is very much like a drug, I'm hooked. If I play the same piece of music over and over pretty soon it gets boring and has no effect and doesn't stir the same emotions etc., so then I have to move on to something else, forever hunting for the next hit. (pun intended? - possibly)
Music is very clever stuff, it has a lot of different levels on which it can be enjoyed. I absolutely hated it and didn't see the point until I was around 13 and saw Oasis on Top Of The Pops. There was something in it I could relate to, so I got interested, started to buy records, started to think about how it had been made, the lyrics, song structures, technical ability required, bought a guitar, learned a load of stuff, moved on from simple to more 'harder stuff' (more complex/heavier) when I got bored. It became one of my many hobbies/obsessions and I pushed it as far as I could be bothered to. Also it's a good way to be sociable but as usual with things I take an interest in I be sociable to enhance the hobby not have a hobby to enhance my social life. But over-analyzing and overexposure to things takes away their magic for me, so now most music I find pretty boring, but I keep listening in case I come across something unique or realize something new about something I have played to death. There's probably a lot more to it than this, like putting something on to enhance mood etc but out of the handful of posts I read no one had this take on it so here you go.
Edit: One other thing I would add is that the type of music you listen to/are involved in can have a strong tie with/impact on identity and lifestyle, which one influences the other I don't know, e.g. feeling as though you belong to a certain group/trend which at the same time has some sort of uniqueness associated with it which distinguishes you from other groups. It can influence what clothes you wear, how you speak, hairstyles (although never has with me).