Imagine you're circling a crowded parking lot. Just as you spot a space, another driver races ahead and takes it. In a world of road rage, domestic violence, and professionally angry TV and radio commentators, your likely response is anger, even fury. Now imagine that instead of another driver, a cow has lumbered into that parking space and settled down. Your anger dissolves into bemusement. What has changed? Not just the occupant of the space but...