Imagine a neighbor who never waters his lawn. But whenever you turn on your sprinkler system, the water falls on his lawn. Your grass is turning brown and dying, but Bill looks down at his green grass and thinks to himself, “My yard is doing fine.” Thus everyone loses: your efforts have been wasted, and Bill never develops the habit of watering his own lawn. The solution? As Cloud puts it, “You need some fences to keep his problems out of your yard and in his, where they belong.”
