The people that lend you money basically give you an answer based on the risk that they are willing to take. But just because a bank is willing to take a particular risk doesn't mean that that is the right amount for me to spend.

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

Rainy day savings are incredibly important, because from time to time, bad things happen. And if you're not prepared for that, it's going to be really terrible.

When it comes to the mental world, when we design things like health care and retirement and stock markets, we somehow forget the idea that we are limited. I think that if we understood our cognitive limitations in the same way that we understand our physical limitations … we could design a better world.

...[D]ivision of labor, in my mind, is one of the dangers of work-based technology. Modern IT infrastructure allows us to break projects into very small, discrete parts and assign each person to do only one of the many parts. In so doing, companies run the risk of taking away employees' sense of the big picture, purpose, and sense of completion.

But suppose we are nothing more than the sum of our first, naive, random behaviors. What then?

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.