"I believe alien life is quite common in the universe, although intelligent life is less so. Some say it has yet to appear on planet Earth."

"However difficult life may seem, there is always something you can do and succeed at. It matters that you don't just give up."

"Some people say I have a chip on my shoulder but it is actually my chin."

"When I gave a lecture in Japan, I was asked not to mention the possible re-collapse of the universe, because it might affect the stock market. However, I can reassure anyone who is nervous about their…"

"I wouldn't compare it to sex, but it lasts longer."