People who really want to make a difference in the world usually do it, in one way or another. And I've noticed something about people who make a difference in the world: They hold the unshakable conviction that individuals are extremely important, that every life matters. They get excited over one smile. They are willing to feed one stomach, educate one mind, and treat one wound. They aren't determined to revolutionize the world all at once; they're satisfied with small changes. Over time, though, the small changes add up. Sometimes they even transform cities and nations, and yes, the world.