Paranormal Activity

Why is it that we as people love to scare the bejesus out of ourselves?!

I can't even remove myself from that category since last night I willingly watched Paranormal Activity 2 at a friends and then went to the theaters to watch Paranormal Activity 3 at 10:30 at night.
What is it about scary movies that has us so intrigued?  Enough to endure the aftermath of having to return home at 3am to my empty apartment and then attempt to sleep?
I went with a group of my guy friends, so of course they all made endless jokes about me jumping at every movement and my continual outbursts of "Jesus!" "Oh!" and other various squeals and noises that did not actually amount to words.
I kept telling myself that my 10 year old nephew went and saw this in theaters. There is no reason I shouldn't be able to.
But my 10 year old nephew is not a young female, living alone in an apartment with paper thin walls where you can hear your neighbors peeing or phone vibrating making for a lot of unaccounted for noise.
Ok, so technically I don't live alone, as I have a roommate, who comes home about once a month to pay bills and then returns to "staying" at her boyfriend's. But technicality aside, I live alone.
Regardless, somehow mass amounts of people, willingly pay to feel like this:

And even though I was one of the many partaking last night, I still can't tell you why. I don't even like scary movies.