who visits you when you sleep?

i was sleeping peacefully and was vaguely aware of myself rolling to my left to continue sleeping on my side. then suddenly, i felt a slight stirring behind me, as if there's someone sleeping next to me on the bed, as well as a slight sinking of the bed. i thought, "ah shucks, not again!" and started chanting.

i tried to chant out loud, but no sound came out of my mouth. i can't move a muscle nor even open my eyes. but as soon as i started chanting, i can feel the "pressure" lifting off me with again, some stirring on my bed as if a heavy object has been lifted off the surface.

when i felt that i'm completely free to move again, i opened up my eyes and saw the clock reading 4:00am. damn! my heart pounding, i quickly looked around my room, but everything is in order as they should be. but now that i'm wide awake, i'm just angry. another interrupted sleep! blardy hell! took me more than an hour to fall asleep again, and then it's time to wake up for work. double damn!

actually this is not the first time this has happened to me. the first time was during my secondary school, form 4 i think. scared the hell out of me! up until now, i've experienced it for 5-6 times, in bear hill, in bkt jalil, and now in sandland.

according to chinese lore, this is called "pei kwai jak" (cantonese: pinned down by a ghost). in other cultures, they refer to it is "hag phenomenon" or "old hag syndrome". basically, the symptoms are about the same, with slight variations depending on the person. at first, i too thought that i was visited by some supernatural thingy. the first few times, i daren't even tell anyone. then another time when that happened and i told my parents, my mom said it could be because i missed my gongyo the night before.

then lately, i came across an article about "sleep paralysis" and the symptoms are what i've experienced, except that i had them while lying on my sides instead of on my back as reported by many others. so there's actually a scientific explanation for it! but they still can't explain about the hallucination (is the sinking sensation of the bed and stirring behind me really a hallucination?) though.

anyway, i'm more calm now, whenever i'm "pinned down", coz i know it's not really a supernatural visitation and i'm not about to be possessed by a ghoul or kidnapped by the aliens. but that doesn't dispel the initial fear when i feel the first stirrings behind me. after that, i'm just hell pissed that i'll have trouble going back to sleep, which will make me even more pissed! why am i always being inflicted with all these sleep problems??