I can see that as one way I'd be scared of such things, but having pondered it some more I think it's different than that. I think the fear centers on thinking about encountering someone with this sort of problem. And I think maybe the reason that scares me has to do with some things I experienced as a kid.

For one thing, I started remembering times growing up when my younger brother, who shared a room with me, would say weird things in his sleep. Occasionally he'd do things (get up, walk around, start conversations) that had me thinking he was awake, but when I'd try to talk to him, he'd not recognize that I was there. That could be VERY creepy in the middle of the night, having my brother seem to be someone he wasn't, or having him seem to not recognize me, or not recognize that I was even there.

What that sort of experience does, in part, is to make me question my own interpretation of events. "Is he sleepwalking, or am I dreaming? Am I even here?"

Also, I'm prone to the same sort of sleeping weirdness. I come half awake sometimes and have all sorts of strangeness running through my head, sort of dream-logics that I impose onto the real world, which I'm only half perceiving. Sometimes I'll wake up fiddling with something on my dresser, trying to "turn off" some picture frame, or to find some object that in my increasingly awake state I can't remember what (it) is.

Those experiences are somewhat frightening, and the thought of encountering a person behaving in a similar manner while "awake" is therefore creepy to me.

One time that thinking about that sort of thing REALLY got me creeped out was when I worked the graveyard shift at a 7-11. Before heading to work I had watched a show in Alien Hand Syndrome, and then while at work I just kept thinking about tricks or perception, and then I thought about how some person could come in there who was so utterly weird looking, deformed or something, and I might not see that person because my mind might ignore what I saw as it was so out of place.

(I understand that that last little bit went completely outta whack, sort of like i were talking in dream logic right there out in the waking typing world. So anyway, part of what scares me about all that IS thinking about how my brain might trick me in such a way.)

Okay!