The U.S. started with no stars. In fact, it started with a completely different flag. The last two were added in 1959, Hawaii and Alaska.

The definition of who's literate and who's not keeps changing. So, in Neanderthal times, if you painted on a cave wall, that was enough to transmit how you hunt, how you eat, how you cook, how you dress, and we can read about that.

When you brought the digital revolution in, all of a sudden, you could build a country like Singapore and take that country, which had the income per capita of Ghana in 1965, and make it something similar to the United States in one generation.

Since the 1940s, we've been saying there are no differences, we [humans] are all identical. We're going to know at year end if that is true.

The thing that keeps me most awake is the desire and curiosity to learn more.

One of the lessons that I hope people will take out is the extreme dependence simply on the financial sector is really dangerous.

There's a creativity, a power, an energy, an ability to do things unlike any other period in history. It's a little bit like sitting in the Renaissance, but multiplied a thousand-fold.