Yes, it was terrifying. I woke up in the middle of the night and found I could not move my legs or my left arm. My right arm was fine, strangely, so I looked down, picked up my hand, and started moving it around like a ragdoll. I didn't know what the fuck was happening, and I didn't immediately think of sleep paralysis, so I started to panic. I felt I had just woken up from a dream, but I couldn't remember what it was. No hallucinations, I don't think. It can't have lasted more than a minute, but it felt like forever. After a while, I felt sort of a rush, like blood returning to my limbs, and I could suddenly move again. It was very surreal.