Wow, that was a great flash piece.
Ususally I don't find myself applying that g-word to flash. Sure, "amusing," or "fun," or "chilling," and this also was both of those.
Also, it helped me realize something about myself as a reader.
I've had a boilerplate argument I've made since I was a teenager that goes something like this: Horror which is purely psychological is by nature the best horror. My favorite King story, for example, was always Secret Window, Secret Garden. The argument ran along lines of "it's better because it doesn't have to resort to the crutch of the supernatural, and is thus more immediate."
As I thought about my response to this story, I realized there was a much better explaination.
A truism of horror, and one which almost seems like it goes without saying, is that the best horror is that which touches on what the reader finds genuinely terrifying. It makes sense that an arachnophobic person would get much more of a rise out of a story about evil spiders than one about evil chinchillas.
I have a pretty healthy relationship with fear. I have a natural, healthy fear response, but I'm usually pretty in control of fear, and I try not to dwell on it.
But perhaps the very rationality that allows the former accounts for my intense terror at the idea of my own mental processes becoming unreliable. About a week ago I ran into an old friend who was pretty clearly delusional, probably paranoid schizophrenic, and I was floored by the experience for the rest of the day.
It was probably the story coming in such close proximity to that highly unpleasant meeting that led to this realization: I most probably find psychological horror, espescially the kind told by an unreliable narrator who doesn't recognize his own delusion, so effective because that's what most scares me.
Also, I love it when a writer takes you one step beyond the punchline you thought you saw coming.