Excerpt on size,
A city can't be too small. Size guarantees anonymity—if you make an embarrassing mistake in a large city, and it's not on the cover of the Post, you can probably try again. The generous attitude towards failure that big cities afford is invaluable—it's how things get created. In a small town everyone knows about your failures, so you are more careful about what you might attempt. Every time I visit San Francisco I ask out loud "Why don't I live here? Why do I choose to live in a place that is harder, tougher and, well, not as beautiful?" The locals often reply, "You don't want to live here. It looks like a city, but it's really a small village. Everyone knows what you're doing" Oh, OK. If you say so. It's still beautiful."