I was hugely impressed... was the ultimate example of a man who knew what he didn't know, was perfectly willing to admit it, and didn't want to leave until he understood. That's heroic to me. I wish every grad student had that attitude.

Experience is often the most valuable thing you have to offer.

I was trying to put myself in a bottle that would one day wash up on the beach for my children. If I were a painter, I would have painted for them. If I were a musician, I would have composed music. But I am a lecturer. So I lectured.

I understand the arguments about how the billions of dollars spent to put men on the moon could have been used to fight poverty and hunger on Earth. But, look, I'm a scientist who sees inspiration as the ultimate tool for doing good. When you use money to fight poverty, it can be of great value, but too often, you're working at the margins. When you're putting people on the moon, you're inspiring all of us to achieve the maximum of human potential, which is how our greatest problems will eventually be solved. Give yourself permission to dream.

If nobody ever worried about what was in other people's heads, we’d all be 33 percent more effective in our lives and our jobs.

I always thought every day was a gift, but now I am looking for where to send the thank you note.

What is the most appropriate thing to say to a friend who was about to die. He answered:”tell your friend that in his death, a part of you dies and goes with him. Whenever he goes, you also g. He will not be alone".