Yeah I've thought about that before. Imagine how fucking horrifying it would be to wakeup and not be able to move. It would feel like you were totally swallowed by 3-5 extra people, out of breath, and in pain.  That actually happens. The people who experience it say that it feels as though they are held down by an elephant and that it is terrifying. In prior centuries people tried to explain it by saying they were held down by an invisible demon. Today we call it sleep paralysis. https://en.m.wikipedia.org/wiki/Sleep_paralysis My best amateur explanation is that the brain has a chemical or process for paralyzing the body while we sleep. This (for most people) prevents us from sleepwalking, even though the brain sends the signals to walk. Sometimes this process kicks in a bit early, or it persists a bit after we wake up.  But for most people most of the time, it synchronizes well with the loss of consciousness so we never notice it. It's really an impressive achievement that the body can do this and get it right so often.