h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

Has anyone mentioned this one yet?

If you say something that is overly daring, especially in regards to not believing in ghosts or something like that, you are tempting fate with your words and running the risk of jinxing yourself. An historic example was when the financial backers of the Titanic were so certain they had built a ship that couldn't possibly sink and proudly went around telling everybody.

It then consequently sank. Why? Nobody knocked on wood.

Well, if you find yourself daringly challenging the fates, just immediately rap a few times on a nearby piece of wood. This is supposed to rile up any evil spirits that might be nearby eavesdropping and you'll scare the evil spirits away so they can't seek to do you harm.

Yeah. I think it's a load of dingoe's kidneys too but it's a great Old Wives' Tale. I think it was designed about two hundred years or so ago, when there were admittedly a lot more trees around then there are now.

Now in modern times, wood's not always readily nearby. It is just as appropriate to knock on formica or plastic or whatever happens to be nearby, so long as you say out loud, "knock on wood" while you're doing it. Or so some believe. Perhaps this worked some centuries ago, but times change.

Nowadays, the evil spirits look up and notice you when you knock on wood. They were in the other corner playing cards and being bored but when you knock on wood and they immediately grab the remote control and hit a button that replays the last seven seconds of your life. Then they hear what it is you're trying to scare them away from and consequently your life is ruined by trying to avoid the bad luck. The evil spirits are a little smarter nowadays then they used to be.

I always thought that "knock on wood" came from pagan times, when the trees were seen as sacred. They knocked on wood to please the spirits of the trees. Then the spirits would help them. It is particuarly effective to do this but use someones head instead of wood. Works a treat every time!!