Once lied on bed, and being how you say.. half asleep? But was laying in bed like that, suddenly got the feeling like I was falling down, and apperantly while beeing in such a state, I had rolled to the edge of bed, and fell off, and woke up right before I hit the floor.. Kind of hurt, lol.
But umh, worst one was probably when I was alot younger (dont remember what age), but woke up by my mother crawling into my bed, hugging me and crying, saying that grandma had died. :x