my mom says she found me sleeping on the floor when i was little, but now i never fall out of bed. It's like i'll stop myself from taking that extra turn. Sometimes I'll find myself almost falling off. The energy needed to keep yourself from falling off is pretty painful though, especially when you still want to stay asleep.
When I was younger I use to fall out of bed all the time, it's definitely not the greatest feeling in the world, especially when you have hardwood floors. It was about a foot from my mattress to the floor, so it was a pretty big fall. I'm just fortunate I've never landed on my head.
With that being said, I haven't fallen out of bed in a real long time.
When I moved back home, before I moved all my stuff in, I was sleeping in the then spare room in a single bed. Because i'm used to a queen size, I rolled over and fell out. I did that every night until I moved my bed in there.
When I was a little girl my sister and I shared a bunk bed. I slept on the upper bed and I recall one night I felt a hard something on my head, I found myself on the cold marble floor. I wondered how I got there and then just climbed up again and continued to sleep.