I just went through this at 4am this morning. The same song playing in my head over and over. And I was having the same conversation with myself over and over at the same time. It's not a new experience to me.It happens more than I care to admit. It's maddening. I never knew if this was "normal" and other people experienced this. I was scared to ask anyone, really. Is this what you call mania? I feel some sort of relief that I'm not alone and sad too that anyone has to deal with this. I have no way of coping with it, I just hope that some other distraction will come along and snap me out of it.