“First of all, I want you to think of the city as a collection of people. That's easy, right? You think of Minneapolis or Chicago or Milwaukee, you think of hundreds of thousands of people. Millions of people. That's what you think of right away. Maybe you think of sky-scrapers too, I don't know. But I think of people. The next thing you should think about is ideas. Think of each of those millions of people as a set of ideas. Like, That woman is a ballerina, she thinks about ballet. Or, that man is an architect, he thinks about buildings. If you begin thinking about it that way, a city is the greatest place in the world. It's millions of people, brushing up against one another, exchanging ideas, all the time, at every hour of the day.”