A day of bloody mayhem?

So, it’s Friday the 13th tomorrow. Why is Friday the 13th alone considered frightening, a day on which gruesome things might happen and homicidal maniacs go berserk? Why not Tuesday the 13th, or Wednesday the 13th, or Sunday the 13th? Is it because of the movie “Friday the 13th”?

I didn’t learn about the “significance” of Friday the 13th until I saw the movie, when I was in the 7th standard, I think. I didn’t know it was a horror movie. Yeah, call me stupid, but that’s how it was. I can’t actually remember with whom I saw it, and I've no idea how I was allowed to see it (shouldn't it have been an adults-only rating?).

I do know that I was all excited to be going for a movie, and I CERTAINLY remember my horror at the first killing (about five minutes into the movie, I think) and then all the subsequent murders - the body of a guy in a bright blue-check shirt was discovered when it swung upside down into the surviving girl's face (or something like that). I vividly remember the end when the last girl to be alive is pulled into the water by a corpse, because I actually screamed. It was meant to be a dream, but I’m not sure. That was my first ever slasher movie, and I’ve never been a fan of that genre.

But to get back to Friday the 13th... any ideas about how the superstitions began? Surely it wasn’t just a crappy 1980s Hollywood movie that started it - or should I not go into the basement or the garage or anywhere dark and lonely tomorrow, just to be on the safe side? (The one place I’m not afraid of going to tomorrow is work – every day is a horror show anyway.)