When they say the sky's the limit to me that's really true

The secret to creativity is knowing how to hide your sources.

Great work requires great and persistent effort for a long time. … Character has to be established through a thousand stumbles.

If you spend too much time thinking about a thing, you'll never get it done.

I am always doing what I cannot do yet, in order to learn how to do it.

If my mind can conceive it, and my heart can believe it - then I can achieve it.

You'll never do a whole lot unless you're brave enough to try.

To be yourself in a world that is constantly trying to make you something else is the greatest accomplishment.

The secret of genius is to carry the spirit of the child into old age, which means never losing your enthusiasm.

The meaning of life is that it is to be lived, and it is not to be traded and conceptualized and squeezed into a patter of systems.

It's always too early to quit.

Scar tissue is stronger than regular tissue. Realize the strength, move on.

First ask yourself: What is the worst that can happen? Then prepare to accept it. Then proceed to improve on the worst.

The fact that the great scientist believed in flying machines was the one thing that encouraged us to begin our studies.

Keep your face always toward the sunshine - and shadows will fall behind you.

My advice to other disabled people would be, concentrate on things your disability doesn't prevent you doing well, and don't regret the things it interferes with. Don't be disabled in spirit as well as physically.

One person with a belief is equal to a force of ninety-nine who have only interests.

A superior man is modest in his speech, but exceeds in his actions.

One must maintain a little bittle of summer, even in the middle of winter.

Ability is what you're capable of doing. Motivation determines what you do. Attitude determines how well you do it.

You can chain me, you can torture me, you can even destroy this body, but you will never imprison my mind.