happened a few times when I was about 17-18. it was pretty scary. I remember clearly 3 times. 1: I was aware in my head but couldn't open my eyes or move, I was like trapped in the dark of my closed eyes. 2: I opened my eyes but couldn't move, I could only move my eyes sideways then I saw a tread moving like an inch worm and that made me understand that I must be half-way between wake and dream. 3: I opened my eyes, couldn't move but somehow I managed with a lot of effort of will to like pull out my "spirit" arm out of my physical are and touch my head while my physical arm just stayed there, like a semi-out-of-body experience. no1 and no2 type of experience I'm pretty sure happenned a few times, made me scared to fall asleep for a while. then I had a weird period where it was just like something would wake me up by shaking me and I would open my eyes yelling "what do you want?" and there was no one there, THAT was scary. then I left for mexico for a few months and thought it would stop but one night in Chapala I woke up as if someone was playing marakas right next to my ears and when I woke up there was nothing. it felt like it wanted to tell me that even in mexico it can still wake me up, Mexican style. but then all that stopped.
