When I was a lot younger, I saw a TV-program that told scary fairy tales. The story I remember was one where a man came in contact with a flock of small devils. He fought them of and was even able to break off one of the legs of a devil. Years later he encountered the same devil and traded the devils foot for a glass of water that allowed him to fend off death for a while.
Long story just to say that I used to be quite scared of a plain window when there was darkness outside. I always imagined that that devil would come knocking on my window.

So what are/were you afraid? What doesn't sit well when you think of it?