You're probably familiar with these ipod dancer images. But click on the ANIMATION of this one and ask yourself which way she's rotating. Clockwise or anti-clockwise?
The answer seems obvious, because you're seeing it the way that you're seeing it. But then you realise that with a bit of effort you can make her go into reverse. Or back and forth for that matter.
Good, eh? Now figure out what you're going to do for the rest of your day.