At its core, I don't view Facebook as a social network. I think it could become the driver's license of the Internet. And beyond that, it can become the pipes and the plumbing upon what most of the Internet is built. I think it's very well positioned.

The first thing I would do for anyone who's trying to lose body fat, for instance, would be to remove foods from the house that he or she would consume during lapses of self-control.

I discourage passive skepticism, which is the armchair variety where people sit back and criticize without ever subjecting their theories or themselves to real field testing.

Many a false step was made by standing still.

If the challenge we face doesn't scare us, then it's probably not that important.

The goal is not to simply eliminate the bad, which does nothing more than leave you with a vacuum, but to pursue and experience the best in the world.

Focus on impact, not approval. If you believe you can change the world, which I hope you do, do what you believe is right and expect resistance and expect attackers. Keep calm and carry on!