If you think of people as making decisions actively, every time we think about the cup of coffee, we say, "How much will I enjoy the cup of coffee, what else could I not do in the future because I buy this cup of coffee?

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

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

If you have loans, the first thing you want to do is say, "Okay, look I have a credit card, if I really need to borrow, I have this emergency money that I can get, but for now there is no reason for me to keep cash at zero percent interest rate and at the same time, pay all of this money out. So, I think people need to figure out quickly how to pay loans and how much cash they should really keep.

It is very difficult to make really big, important, life-changing decisions because we are all susceptible to a formidable array of decision biases. There are more of them than we realize, and they come to visit us more often than we like to admit.

The companies that provide debt, what do you think their goal is? Is their goal for you to fully understand the cost of your debt? No. So they're basically creating these approaches to make you feel like it is incredibly cheap or just to think about the cost per day rather the cost per year or cost for a lifetime. So debt is very simple mistake.

The problem with opportunity cost is that opportunity cost is divided among many, many things.