Old people think young people haven't learned about love. Young people think old people have forgotten about love.

They won't listen. Do you know why? Because they have certain fixed notions about the past. Any change would be blasphemy in their eyes, even if it were the truth. They don't want the truth; they want their traditions.

Before another century is done it will be hard for people to imagine a time when humanity was confined to one world, and it will seem to them incredible that there was ever anybody who doubted the value of space and wanted to turn his or her back on the Universe.

I even got a letter from a young woman in British Columbia that began as follows: 'Today I am eighteen. I am sitting at the window, looking out at the rain, and thinking how much I love you.'

It has been my philosophy of life that difficulties vanish when faced boldly.

Any system which allows men to choose their own future will end by choosing safety and mediocrity, and in such a Reality the stars are out of reach.

I am not responsible for what other people think. I am responsible only for what I myself think, and I know what that is. No idea I've ever come up with has ever struck me as a divine revelation. Nothing I have ever observed leads me to think there is a God watching over me.