When you ask people, 'What's the opposite of fragile?,' they tend to say robust, resilient, adaptable, solid, strong. That's not it. The opposite of fragile is something that gains from disorder.

Never take advice from anyone in a tie. They'll bankrupt you. Don't ask a general for advice on war, and don't ask a broker for advice on money.

Nature builds things that are antifragile. In the case of evolution, nature uses disorder to grow stronger. Occasional starvation or going to the gym also makes you stronger, because you subject your body to stressors and gain from them.

People have the problem of denial. This is one of the things I learned in Lebanon. Everybody who left Beirut when the war started, including my parents, said, 'Oh, its temporary.' It lasted 17 years! People tend to underestimate the gravity of these situations. That's how they work.

If I ask you to write down the last 4 digits of your social security number, and then take you out to lunch and ask you how many dentists there are in Manhattan, there's going to be a high correlation between those two numbers. What happens is that the number psychologically makes you feel confident.

If you are in banking and lending, surprise outcomes are likely to be negative for you.