The only path by which another person can upset you is through your own thought.

Anyone who has never made a mistake has never tried anything new.

Everything you can imagine is real.

Imagination is more important than knowledge. Knowledge is limited. Imagination encircles the world.

Reality leaves a lot to the imagination.

A clever person solves a problem. A wise person avoids it.

I have no special talents. I am only passionately curious.

If you can't explain it to a six year old, you don't understand it yourself.

Once we accept our limits, we go beyond them.