Many curtains, blinds, shutters and various other window coverings are controlled by string. A loop of string hangs down, you pull one side to close the covering, the other side to open it. Simple.

Except that it's not. Without any obvious markings, you don't know which side does which and you therefore have to guess which side to pull. So far so annoying, but at least there's a 50% chance you'll choose correctly. Right?

Wrong. I always pull the wrong side. Well, not always but I recently conducted a survey and found that I pull the wrong side 90% of the time. How is this possible? You tell me.

In an attempt to subvert this seeming fracture in the laws of probability I conducted an experiment where I intentionally tried to pull the wrong string. The reasoning being that if the trend continued I should wind up pulling the right string 90% of the time. Happy days.

Except that I still got it wrong 90% of the time. So 90% wrong trying to pull the right string plus 90% wrong trying to pull the wrong string equals 180% incorrect string pulls. I think something may be wrong with the space-time continuum. Anybody got Stephen Hawking's phone number?