Alex Kotlowitz explains why Chicago is Fast Company's U.S. City of the Year: "The real Chicago isn't so easy to keep up with. It's constantly reinventing itself. Jumpy. Agitated. Impatient. It's as if the place is trembling. Move aside. Don't linger. And if you're going to dawdle, get out of the way. But what any Chicagoan will also tell you is that the past is very much present. It doesn't go away. It shouldn't. In fact, that's Chicago's lure and its beauty: its ability to take what was and figure out what could be."