I met someone at school today who shares a sleep condition I didn't know existed. I found out that opening my eyes in the middle of a nightmare about demonic possession or being chased by something malevolent and non-human and realizing that I cannot move or call out is called sleep paralysis. Other people experience it as something sitting on their chest so that they feel weighted down or suffocated. Phew, maybe I'm not crazy or in need of an excorcism. Take the survey if you also experience this. Or just read the info here if you're lucky enough to not be plagued by this terrifying disorder.