In the Coast Guard, on the Rush, I never fell out of bed. The ship's taking 30-degree rolls? I never slept better!
At Texas A&M, I slept on the top bunk, and never fell out of bed. I'd regularly jump out of bed (no ladder), turn off my alarm, turn on the shower, get the temperature right -- and then wake up, stretched out in the tub with the shower cascading down on me.
I lived in an RV in high school. Never fell out of bed then.
As a kid, I had one of those "Captain's beds" with the chest of drawers under them -- two rows of drawers, so it was pretty high. I think I'd remember falling from that distance.
We're back more than 30 years now...
Edit: On the plus side, there are few lasting ill effects. I'm sore here and there, but in a mild, achy way, not in an I-can-barely-move way. My elbow hurts where I cut it on the bedframe, and my knees are sore, which baffles me, since I fell on my back, but otherwise, there's just a bit of sore-jointness here and there. And there. And over here. And, ooh, that's kinda hurty.