Sleep paralysis

I experienced it for the first time last night. I was lying on my side, facing the wall. There is a spaced between my bed and the wall, enough to walk through (though its a tight confinement). Near the end of the bed, along the wall, is a window. I was looking at this window, lying on my side, when this black mass appeared. It was a black cloud darker than darkness of night that pervaded my room. There was a very minute amount of light pooling in from the window but this cloud covered it and it grew. I felt as though there was something in the mass that was slowly approaching me, to attack or do God knows what. I couldn't move. I wanted to so badly but I just could not. I could see myself, in my mind's eye, reaching my hands out to push the thing away but I could not actually move anything. I just lay there in distress.

This was both a dream and not a dream. It was a dream in the sense that I "woke up" from something but I lay exactly as I had in the dream, the only difference was that I was finally able to roll over, away from the window. The terror was real. My heart pounded and I breathed heavily upon "waking." So much so that I felt as though I had just gone running.

One effect of sleep paralysis (other than the obvious which is you cannot move) is hallucinations. I've heard a couple other stories but had never experienced something quite like this. The black cloud was the hallucination but everything else was incredibly real, because it was real. When you sleep, your brain releases this chemical that temporarily paralyzes you so that you don't act out your dreams and injure yourself. With sleep paralysis, you wake up but your brain thinks your still dreaming so this is why you cannot move and why you can hallucinate.

Scary. Incredible.

The scariest or most interesting thing to note is that I was talking with someone about this very thing only a few days ago and I deduced that this is what they were experiencing but I told them I've never experienced it before. Perhaps I was meant to experience this then, or maybe it was a weird self-fulfilling prophecy type of thing.