Eli5 why grown ups do not fall down from the bed?

Question

I am wondering why small kids ( even a few years old) fall down from the bed while changing their position but bigger children /adults do not, no matter how much they move while sleeping?

In: 2276

Answer 1

I will add we do fall out of bed! When I was in basic training it happened a lot. We were so beat and tired that the brain was just dunzo. A lot of people falling out of bed during the night.