I have this literally all the time. It isn't freaky because it's normal. Can anyone describe what its absence is like? Do you suddenly become able to move? Are you moving before you wake up?
Often times a movement wakes you up or as soon as you are conscious you are able to move. Waking up and not being able to move is quite a shocking experience. Happened to me once and I thought I was dead. I was very afraid because I knew someone in the room could hurt me and I couldn't do anything about it.
Of course, the same is true if I was unconscious and sleeping as well, but somehow, being awake and unable to respond and being aware made it terrifying.