Personally I've been in hospital once, when I was somewhere between 10 and 15. I was running around in the dark (stupid) and tripped, and knocked my head on a metal table. It missed my right eye by about half a cm, and I can still see the remains of the scar if I squint (I'm 22 now).
I only spent about an hour in hospital from that though, then a quick visit to the doctor a week later to get the stitches removed. It's scary though, because I almost lost my eye 😱