I would have to say that its falling back asleep and getting truely back to sleep. I vary between waking up and going right back to sleep while just thinking of a phrase. other times I will try the approach of get up and do stuff for 20 minutes to get your mind going and then try and go back to sleep. When i do that I try to MILD and turn it into a WILD but each time i have done that I feel like i cant get back to sleep.