When I went off to college, I was expecting to be a concert musician. In music school I heard all of these kids who were just unbelievable. And I understand that you can be very, very good, but there's something that separates very, very good from great, and I knew that I wasn't great.

We [USA] need to deal with our problems here at home if we're going to be strong enough to lead abroad.

When somebody underestimated me, it made me want to prove them wrong.

America cannot do most of what needs to be done alone. You need friends. And we have good friends around the world. We have friends with whom we share values in Europe and Asia - thanks to the forward march of democracy - in Latin America, in Africa, and increasingly in the Middle East.

If you're always in the company of people who agree with you, you're going to think of people who don't agree with you as venal or stupid. I constantly tell my students that if they're in the company of people who always say "amen" to what you say, find other company. And that is the source of illiberalism, when you are unable to listen to someone who thinks differently. That's when democracies are in trouble.

I'm a great believer in the fact that as you get to know someone, it matters not what religious background they have, or what their nationality is, or where they came from. And I think that's how Americans really do relate to each other on a personal level.

We need to move beyond the idea that girls can be leaders and create the expectation that they should be leaders.