Try this really weird game - it's great! You'll need a mirror and someone you know quite well - a friend or someone in your family. Have a look at the other person's face in the mirror. Do you notice anything different about the way they look?

Now, if you were looking at my Dad in the mirror, his wonky nose would go in the opposite direction to the way I'm used to seeing it. This is because when you look in a mirror what you actually see is the exact reverse of what you normally see. Imagine a world that was always back-to-front like this, or upside-down, or even inside out! Well, maybe not inside out - that would be a bit messy!