[Affolfembonge]

It can happen, and there are cases of people who go to sleep and just die as they just never wake back up. That probably does not happen that often. What always gets me... is when I have a very vivid dream where waking up is almost like being thrown into a new world as the dream ends. If I have had one, then I can remember it clearly--even as I have woken up.
On the other hand, while sharing a room, I made the mistake of sleeping oddly. What happened was it was hard for anyone to wake me up, probably due to sleeping on a bent leg or sleeping where I wasn't getting enough circulation or something.

I can remember talking in dreams to people and even remember the colors in the dream at times.