The human mind has a tendancy to want to explain
everything. It's an interesting
phenomenon. Keep people up until
4am and they will start to hear things that are completely normal, in all likelihood. They will of course become
freaked out until their mind whips out what I like to call the
reality stapler and goes after that whippet of
bizzare-ness with a
vengence. If the mind can in any way
rationalize that little nibblet of sound, it will, effectively
stapling that thought down to reality,
anchoring it in the real world.
Things get weird if you try not to use the reality stapler. People who have lost theirs, or at least misplaced it for a while, get scared by the dark, by funny noises, they think they see ghosts, goblins, ghouls, and the like. People who are truly insane have no reality stapler... or at least, they're out of staples. =c)