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

The more cashless our society becomes, the more our moral compass slips.

What reminds you in your environment about saving? Nothing.

Dishonesty is all about the small acts we can take and then think, 'No, this not real cheating.' So if you think that the main mechanism is rationalization, then what you come up with, and that's what we find, is that we're basically trying to balance feeling good about ourselves.

If we all make systematic mistakes in our decisions, then why not develop new strategies, tools, and methods to help us make better decisions and improve our overall well-being? That's exactly the meaning of free lunches- the idea that there are tools, methods, and policies that can help all of us make better decisions and as a consequence achieve what we desire-pg. 241

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.

Imagine you have six loans, small to huge. People want to close loans and because of that, they try to pay off the small loans, but that's not the right strategy. The right strategy, of course, is to pay the loan with the highest interest rate. People make this mistake and it costs them lots and lots of money, it's a very expensive mistake because interest rates accumulate and become very, very expensive very quickly.