Why do superstitions exist?

Superstitions are a means of explaining events, especially tragedy, accidents, illness, and all the other mysteries. When people do not know the actual reason that something happens, they often latch onto circumstances that APPEAR to cause or relate to their misfortune even though those circumstances might be entirely unrelated. This is especially true with people who have very little education or little scientific knowledge.

For example, suppose I enjoy sending and receiving email, even though I don't understand how computers work. Suddenly my computer crashes. Being human, I look around for the cause, and notice that my neighbor's kid is riding a skateboard past my house. I could jump to the conclusion that teenagers on skateboards can cause computers to crash. Maybe I then tell all my friends what happened, and they, who don't have any technical knowledge of computers either, believe it and tell their friends. Before long, a superstition exists about teenagers on skateboards causing computer crashes.

Another reason is that we keep trying to divert back luck, to protect ourselves and those we love from all sorts of perils. Superstitions seem to enable us to do so and, even if they don't work, by performing a certain ritual we assure our subconscious mind that we are no longer in danger, empowering us in our fight with Fate.