Solitude is painful when one is young, but delightful when one is more mature.

Here's a Challenge: Study a complicated topic in such detail that anyone interested can nod their head and understand as you explain specific concepts within the topic.

But there is another reason for the high repute of mathematics: it is mathematics that offers the exact natural sciences a certain measure of security which, without mathematics, they could not attain.

You teach me baseball and I'll teach you relativity...No we must not. You will learn about relativity faster than I learn baseball.

Striving for peace and preparing for war are incompatible with each other, and in our time more so than ever.

No amount of experimentation can ever prove me right; a single experiment can prove me wrong.

The only mistake in life is the lesson not learned.