Academics were not a challenge when I was fifteen in college. The challenge was figuring out how to fit in socially.

The real question is not are there other forms of life in the universe, but are there other intelligent forms of life out there right now. Because the universe is not only really big but it's also really long. It's been around for a long time; it's going to be around for a long time.

Sometimes you check things off because you've done them. If you aren't checking stuff off your bucket list, you aren't living very well.

An emerging market is a country where politics matters at least as much as economics to the market.

I think graffiti is part of Berlin culture. You think about what the Berlin wall meant and how visible that was in everyone's life. How it was a part of their very identity.

In the nearer term, the likeliest source of risk is a conflict between China and the U.S. These are now the two largest economies in the world, and the combination of their economic interdependence, the sharp differences in their political and economic values, and the growing divergence in their interests makes this relationship potentially dangerous for everyone who might be affected by it - which means pretty much everyone.

We live in a fantastically wealthy country. We don't have to worry about food. We don't have to worry about clothing. We don't have to worry about our safety. It's very easy for me to be an environmentalist. It's very easy for me to care about making sure that we protect the forests and the whales, and all that stuff.