Ultimately, the complex folklore of Friday the 13th doesn't have much to do with people's fears today. The fear has much more to do with personal experience. People learn at a young age that Friday the 13th is supposed to be unlucky, for whatever reason, and then they look for evidence that the legend is true. The evidence isn't hard to come by, of course. If you get in a car wreck on one Friday the 13th, lose your wallet, or even spill your coffee, that day will probably stay with you. But if you think about it, bad things, big and small, happen all the time. If you're looking for bad luck on Friday the 13th, you'll probably find it.