"Walking is easy. It’s so easy that no one ever has to teach you how to do it. It’s so easy, in fact, that we often pair it with other easy activities—talking, chewing gum—and suggest that if you can’t do both simultaneously, you’re some sort of insensate clod. So you probably think you’ve got this walking thing pretty much nailed. As you stroll around the city, worrying about the economy, or the environment, or your next month’s rent, you might assume that the one thing you don’t need to worry about is the way in which you’re strolling around the city.
Well, I’m afraid I have some bad news for you: You walk wrong."