Life is like riding a bicycle. To keep your balance, you must keep moving.

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

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

Insanity is doing the same thing over and over again and expecting different results.

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.

Reality is merely an illusion.

Only a life lived for others is a life worthwhile.

Once we accept our limits, we go beyond them.