We are privileged that the dollar is the "currency of last resort" and the most important currency in the world. Global commodities are priced in dollars. Central banks in other countries hold great quantities of dollars. The dollar was the safe harbor, the port in the storm during the credit crisis.

I don't think money can be understood through a lens limited to economics. And most books about money tell you the history of money, the instrument. But money is also an idea, one that we exchange to survive.

Money is becoming increasingly plastic and digital. If there is a major disaster, let's say an asteroid strike, we'll go back to trading meats and furs. We won't need an abstraction, a dollar bill, but real tangible goods to survive.

All organisms rely on exchange. They form symbiotic partnerships in order to obtain the energy that they need to survive. Energy is the currency of nature.

Researchers have found that identical twins who have been separated for long periods of time actually invest in a similar manner. Biology really does affect how we spend money.

The oldest and most important currency is debt.

We don't invest in financial literacy in a meaningful way. We should be teaching elementary school children how to balance a checkbook, how to do basic accounting, why it's important to pay your bills on time. First, education. Begin the learning process as early as possible, in elementary school. Second, encourage and support entrepreneurism. Third, policy. I know it's a priority of the US Treasury to augment financial inclusion and increase financial literacy.