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

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

The key to immortality is first living a life worth remembering.

Neither worse then or better is a thing made by being praised.

To See a World in a Grain of Sand And a Heaven in a Wild Flower, Hold Infinity in the palm of your hand And Eternity in an hour.

I will never be by violence constrained to do anything.

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

I don't know who my grandfather was; I'm much more concerned to know what his grandson will be.

When I'm inspired, I get excited because I can't wait to see what I'll come up with next.

Everything you can imagine is real.

Be miserable. Or motivate yourself. Whatever has to be done, it's always your choice.

Laziness is nothing more than the habit of resting before you get tired.

Freedom from the desire for an answer is essential to the understanding of a problem.

All the darkness in the world cannot extinguish the light of a single candle.

You are never too old to become younger!

You yourself, as much as anybody in the entire universe, deserve your love and affection.

A man may die, nations may rise and fall, but an idea lives on.

In a conflict between the heart and the brain, follow your heart.

I hated every minute of training, but I said, 'Don't quit. Suffer now and live the rest of your life as a champion'.

For a man who no longer has a homeland, writing becomes a place to live.

The superior man thinks only of virtue; the common man thinks only of comfort.