Do you ever find yourselves having an internal monologue - well hell, of course it is a monologue, I don't have multiple personality disorder - well, anyway.
You're having an internal thought process while you are trying to fall asleep and this leads to that and that leads to the thing over there, and then you shock the hell out of yourself when you are almost 90% asleep and jerk yourself awake thinking, "Wait a minute, how did I get to THAT?" Then you backtrack to the point where you almost started, and you start all over again.
Yeah, eventually I put myself to sleep this way.
Um, how did I come to think about this question, anyway??? :-P