Motivation, basically getting people to be happy at work, everybody - everybody benefits.

In life we encounter many people who, in some way or another, try to tattoo our faces.

I think we could get people to both be more productive and happier. We're less productive as individuals. We're less productive as companies, and we're more miserable.

When you're in pain, tomorrow doesn't exist - just the pain - and the only thing that you want in the world is for it to go away.

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.

Even the most analytical thinkers are predictably irrational; the really smart ones acknowledge and address their irrationalities.

Imagine you owe on five credit cards, you owe five debts. So which debt should you pay first? And the answer is very simple: You should pay the one with the highest interest rate first. But that's not what people do.