It's strange that I seem to be the only person that didn't get freaked out the first time I had SP. I found myself awake in my bed, but unable to move (luckily no hallucinations I guess). It was a bit unnerving sure, but I just assumed it had something to do with me just waking up from dreaming (I'd never heard of SP or REM atonia before). After a few minutes of trying to move, it just decided to go back to sleep.