A very simple bad decision is to get into debt. And that is very expensive.

One percent of people will always be honest and never steal," the locksmith said. "Another one percent will always be dishonest and always try to pick your lock and steal your television. And the rest will be honest as long as the conditions are right - but if they are tempted enough, they'll be dishonest too. Locks won't protect you from the thieves, who can get in your house if they really want to. They will only protect you from the mostly honest people who might be tempted to try your door if it had no lock".

I always found the appeal to the market gods a bit odd. Why would the market fix mistakes instead of aggravating them?

If you want to spend more money in restaurants, use credit cards more than cash. If you want to spend less, use cash more than credit cards. But in general, we can think about how to use the pain of paying and how much of it do we want. And I think we have like a range. Credit cards have very little pain of paying, debit cards have a little bit more because you feel like today, at least it is coming out of your checking account, and cash has much more.

We have very strong intuitions about all kinds of things — our own ability, how the economy works, how we should pay school teachers. But unless we start testing those intuitions, we’re not going to do better.

Once you break the social norm and create a new social norm, all of a sudden it can stay with us for a long time.

Thinking is difficult and sometimes unpleasant.