You can think about life as a battle between you and a doughnut shop. The doughnut shop wants you to eat another doughnut and pay the money, and you want to do it in the short term, but in the long term it's not good for you either financially or from a health perspective.

While we somehow understand revenge on an intuitive level between individuals, I do suspect that companies, assuming that people are rational, completely miss and underestimate the motivation people have for revenge.

None of us always make the best financial decisions.

The retail industry has its own headache: it loses $16 billion a year to customers who buy clothes, wear them with the tags tucked in, and return these secondhand clothes for a full refund.

With everything you do, in fact, you should train yourself to question your repeated behaviors.

For all of us, it's very hard to think about money, and because of that, we need help. In the same way that for all of us, it is hard to eat well, and we need some help. The poor have a particular challenge, which is that their life is actually much more complex - and they're much more complex cognitively.

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.