The 10,000-hours rule says that if you look at any kind of cognitively complex field, from playing chess to being a neurosurgeon, we see this incredibly consistent pattern that you cannot be good at that unless you practice for 10,000 hours, which is roughly ten years, if you think about four hours a day.

Starting epidemics requires concentrating resources on a few key area. The Law of the Few says that Connectors, Mavens, and Salesman are responsible for starting word-of-mouth epidemics, which means that if you are interested in starting a word-of-mouth epidemic , your resources ought to be solely concentrated on these three groups. No one else matters.

There’s this powerful phrase in the legal world, “Difficult cases make bad law.” The exception is the difficult case. You can’t generalize them by definition. So although they are fascinating, they don’t solve any problem because they’re so one of a kind.

A study at the University of Utah found that if you ask someone why he is friendly with someone else, he’ll say it is because he and his friend share similar attitudes. But if you actually quiz the two of them on their attitudes, you’ll find out that what they actually share is similar activities. We’re friends with the people we do things with, as much as we are with the people we resemble. We don’t seek out friends, in other words. We associate with the people who occupy the same small, physical spaces that we do.

If you are going to do something truly innovative, you have to be someone who does not value social approval. You can't need social approval to go forward. Otherwise, how would you ever do the thing that you are doing?

I worry that track is going to enter into an impossibly complicated stage, where our understanding of the complexities of human physiology - and our ability to accentuate and exploit them - is going to make the notion of pure competition impossible.

I have a new way of doing things, and I don’t care if you think I’m crazy.