I stayed up a bit late last night studying quantum rotations, so when I went to sleep I was thinking about Euler angles. Actually, before I fell asleep, I woke up twice thinking, "Oh no! I rotated that axis the wrong way!" and "Oh no! I left a dish in the public kitchen!" Sometimes things get stolen if I leave them in the kitchen, see.
Anyways, at some indeterminate time last night, I sort of woke up again, and I couldn't move. I thought someone had broken into my room and was pinning me to my bed. I even thought I saw him, though my bed sheet was mostly in the way. I think I tried to say, "Hey!" but I couldn't speak either.
That lasted about five seconds, then I could move again. And then I thought, "Oh, sleep paralysis," and went to sleep again.
I don't know much about sleep paralysis, except that it occurs when you are falling asleep or waking up. Subjects usually get the feeling that some conscious agent is involved, though the nature of the agent is culture-dependent. It's not surprising that I interpreted it as an intruder, since the previous night, my apartment residents were talking about someone who keeps stealing food from the refrigerators. But many past cultures have interpreted them as demons, and in more modern times, as alien abductions.
Alien abduction is one of those classic skeptical topics discussed by Carl Sagan in The Demon-Haunted World. Though we rarely have to deal with alien abduction claims, I feel that it's still an extremely important demonstration of some skeptical concepts. Alien abductions are one of those paranormal claims which really do have something to them. It's not quite so extraordinary as aliens performing live dissections, but sleep paralysis is pretty amazing too.
Anyway, when countering alien abduction claims, it's important to affirm the reality of those experiences. People have a bias against believing anything unflattering about themselves, so if you tell them that their experiences are fake, they'll reject what you say. But it's not just a matter of strategic positioning, it also happens to be true that the experiences are real. Alien abductees aren't liars.
And for the same reasons, it's important to emphasize that alien abductees are not crazy either. Sleep paralysis is actually fairly common, and it's frequently accompanied by convincing hallucinations. I've only experienced it once or twice myself, but I have friends who've had it more often. One of my friends says she gets it like once a month. It's usually quite a scary experience, though it's not as bad as night terrors, which she has much more often. Once she showed me a picture she drew to help her deal with night terrors. It was a picture of a demon making photocopies instead of trying to kill her.
Frequent sleep paralysis probably constitutes some sort of sleeping disorder if it interferes with one's sleep, but it's silly to think that it makes someone a worse person in any way.