Just when you think you know someone, you find out they are not quite the person you thought they were. Take George Clooney for instance. Did you know that Clooney was a habitual prankster? Well, he is. And I think that's hilarious. He has pranked fellow stars like Bill Murray, Matt Damon, Brad Pitt, and many more.

So the lesson is this: If you're ever in the same area as George Clooney, watch your back, or just enjoy the humor, and plot ways to get him back.