The brick walls are there to stop the people who don't want it badly enough. They are there to stop the other people!

You can always change you plan, but only if you have one.

The questions are always more important than the answers.

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.

I didn't know there was a dying-professor section at the bookstore.

A lot of people want a shortcut. I find the best shortcut is the long way, which is basically two words: work hard.

It's easy to be smart when you are parodying smart people.