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.

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

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

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

Only a life lived for others is a life worthwhile.

Things are only as black as they seem.

Once we accept our limits, we go beyond them.