Friday the 13th: The Unluckiest Day on the Calendar... or Just the Best One for Selling Movie Tickets?

There are two kinds of people in this world.

The first kind sees Friday the 13th on the calendar and goes right on about their business. They go to work, mow the grass, and stop by the grocery store for a gallon of milk.

The second kind won't get on an airplane, won't sign a contract, and might not even leave the house.

Somewhere in the middle is the rest of us. We laugh about the superstition, but if something goes wrong on Friday the 13th, we can't help but think, "Well, I reckon I should've seen that coming."

So where did this idea come from? Truth is, nobody knows for sure.

The number 13 has made people nervous for a long time. In many ancient cultures, the number 12 was considered complete. There are 12 months in a year, 12 signs of the zodiac, and 12 Olympian gods in Greek mythology. Then along comes 13, like an unexpected cousin showing up at Thanksgiving and asking if he can stay the weekend.

In Christian tradition, there were 13 people at the Last Supper, and the thirteenth guest was Judas Iscariot. That certainly didn't help the number's reputation.

Then there's Friday itself.

According to Christian tradition, Jesus was crucified on a Friday. Over the centuries, Friday picked up a reputation as a day when unfortunate things happened.

Put an unlucky number together with an unlucky day and you've got a superstition with some staying power.

Another popular theory points to October 13, 1307, when King Philip IV of France ordered the arrest of the Knights Templar. The event happened to fall on a Friday, and some historians believe it helped strengthen the fear of Friday the 13th, though the connection wasn't made until centuries later.

Then Hollywood came along and really put this superstition on steroids.

In 1980, the movie Friday the 13th introduced the world to a hockey-masked killer named Jason Voorhees. Never mind that Jason didn't even wear the famous hockey mask until later in the series. The movies were a hit, and suddenly Friday the 13th wasn't just a superstition anymore. It became a brand.

Hollywood has made a small fortune convincing us that bad things happen on Friday the 13th. There have been sequels, television shows, comic books, and enough camp counselors meeting unfortunate ends to keep an entire chainsaw factory in business.

The funny thing is that researchers have never found any evidence that Friday the 13th is more dangerous than any other day. In fact, some studies suggest people are extra careful on Friday the 13th because they think something bad might happen.

That's probably the story of most superstitions.

They begin with old beliefs, gather a little folklore, pick up a few legends, and then somebody in Hollywood figures out how to turn them into a box office hit.

So if Friday the 13th rolls around and you're feeling a little uneasy, don't worry too much.

Just avoid abandoned summer camps, mysterious cabins in the woods, and anybody carrying a hockey mask.

You know... just to be safe.