Anyone who has ever scanned the bookshelves of a new girlfriend or boyfriend- or peeked inside his or her medicine cabinet- understands this implicitly; you can learn as much - or more - from one glance at a private space as you can from hours of exposure to a public face.

In fact, researchers have settled on what they believe is the magic number for true expertise: ten thousand hours.

There are moments, particularly in times of stress, when haste does not make waste, when our snap judgments and first impressions can offer a much better means of making sense of the world.

If we think about emotion this way - as outside-in, not inside out - it is possible to understand how some people can have an enormous amount of influence over others. Some of us, after all, are very good at expressiing emotions and feelings, which means that we are far more emotionally contagious than the rest of us.

The act of facing overwhelming odds produces greatness and beauty.

People at CDC [Centers for Disease Control] who cut their teeth on diseases over the last 10 years have started to think of crime as another disease, and using some of these same concepts. It was something that was in the air in that world, but it was time to bust it out and apply it to any number of different social epidemics.

I interviewed one of the most powerful lawyers in the world and he told me, "At the time, it was the worst thing in the world not to be able to get a job at a fancy law firm, but it's the greatest thing that ever happened in my life." It was a humble acknowledgment of how forces much larger than himself shaped his career. I really wanted to bring that point home.