Zombies. I always wonder what I would do if zombies suddenly started attacking my town. Considering my neighbor hood I'd probably think it was some crackhead at first.
It drives me nuts, because I know that zombies won't ever attack...or exsist my game or movie standards. But, at least 1-2 times a week I think about my contingency plan for a zombie attack.
This may sound stupid, but it probably comes from playing so many zombie games (RE Series) and watching zombie movies. Cataching myself yelling at the TV, "You Idiot! Man, if I were in that situation I would..."