This is why you wear a helmet.
Let's all be honest with ourselves for a moment, watching crashes can be pretty entertaining at times. So how do we make it more entertaining? Crashes in slow motion, on dirt bikes. Thanks to the slow motion in the following video, even though the rider is wearing a helmet, you can just about see the look on his face when he realizes that it's all gone horribly wrong. It's right when his foot hits the ground, you'll see it.
Don't worry, the guy in the video is fine... probably. We have no idea.