If the whole process of learning from failure means discarding stuff that's not working, but in fact, our natural reaction is to keep going, to throw more money behind it, to throw more emotional energy behind it... that's a real problem.

I see the God complex around me all the time in my fellow economists. I see it in our business leaders. I see it in the politicians we vote for - people who, in the face of an incredibly complicated world, are nevertheless absolutely convinced that they understand the way that the world works.

Accepting trial and error means accepting error. It means taking problems in our stride when a decision doesn't work out, whether through luck or misjudgment. And that is not something human brains seem to be able to do without a struggle.

Loss aversion is a really disproportionate anxiety about stuff that doesn't matter very much. So for instance, if you lose $5, you feel really bad about the $5 you've lost. You're cursing yourself. You're going through it again and again. If, on the other hand, you find $5, you go - hey, great, five bucks. And you've forgotten about it really quickly.

There is much more to life than what gets measured in accounts. Even economists know that.

Each additional child that you have is going to divide your time and your attention. You're going to have to cram them into a smaller house. They're going to have to share rooms, or you might have to move into the suburbs, somewhere cheaper, further away from where the job is.

Trying to be able to have, let's say, more than three partners was absolutely impossible, at least for my own relationships.