What is your daily useless piece of knowledge?

We all know little things about how something works, why something has the name that it does or other little snippets of information that may be interesting, but ultimately useless to know as it does not improve your life.

Just to give an example from myself. In England the police have the nickname Bobbies and this is due to the politician Robert Peel who introduced the Police Act and really set them up as a force. They are therefore called Bobbies due to it being a nickname for someone called Robert.

So what useless piece of information would you like to share with the masses?