I don't know if it's anything. But yeah, I can very much relate. Every moment there aren't 10,000 other things. Parts, over and over and over and over. Don't need to have recently heard it or anything, it's just like a brain ipod with random play loops. I don't even dream about one, but will ALWAYS have one going, at the very moment I awake, middle of the night, whatever, even though the rest of my brain is pretty well non-operational, lol.

It's soooo constant, it would never even occur to me that everyone doesn't have this. The only time it actually bothers me is when it's something I hate. And wow, aren't those persistant?! I'm sometimes able to derail those by really actively listening to something completely different. Sure, it'll come back, but I'll just zap it again. And again. And if something comes on that will likely be problematic, I'll immediately even throw my hands over my ears and make a big buzzing sound or say "blah blah blah blah blah". Card-carrying full-on adult, yup. And I don't care, because yes, the ones I hate, they're that aggravating.