I do not talk to the FBI directors about pending investigations [on Hillary Clinton].

You can’t let your failures define you. You have to let your failures teach you.

Change will not come if we wait for some other person or some other time. We are the ones we've been waiting for. We are the change that we seek.

Keep exploring. Keep dreaming. Keep asking why. Don’t settle for what you already know. Never stop believing in the power of your ideas, your imagination, your hard work to change the world.

When ignorant folks want to advertise their ignorance, you don't really have to do anything, you just let them talk.

Just because we have the best hammer does not mean that every problem is a nail.

Change is never easy, but always possible.

Don’t ever let anybody tell you that your efforts don’t matter or that your voice doesn’t count. Don’t ever believe that you can’t make a difference. You have.

Where you are right now doesn't have to determine where you'll end up.

Learning to stand in somebody else's shoes, to see through their eyes, that's how peace begins. And it's up to you to make that happen. Empathy is a quality of character that can change the world.

If somebody is different from you, that's not something you criticize, that's something that you appreciate.

United States: the country where liberty is a statue.

the hardest thing in life is to accept the facts that are hard to accept and to accept the things you can't accept.

Being here is such a contrast to where I’d otherwise be.

Nothing is so fragile as thought in its infancy; an interruption breaks it: nothing is so powerful, even to overturning empires, when it reaches its maturity.

I don't know any teenager with a positive attitude.

Little is much, If love abides

It's a total injustice. Things like that happen in life.

I don't over-sing anymore, which I used to suffer from terribly because I couldn't hear myself.

It's not enough to just test athletes. The athletes themselves need to fight for their right to compete against clean athletes.

What we will have attained when Neil Armstrong steps down upon the moon is a completely new step in the evolution of man.