I believe that half the trouble in the world comes from people asking 'What have I achieved?' rather than 'What have I enjoyed?'

Imagination can help you reach into the heavens to grasp an idea, bring it down to earth, and make it work.

You've never in your life seen a horse run like this! He's all power - all beauty.

Yet when the books have been read, it boils down to the horse, his human companion, and what goes on between them

Yet when books have been read and reread, it boils down to the horse, his human companion, and what goes on between them.

At some stage of development an officer had to stop following orders and start generating them.

There was no doubt about it: the City was the culmination of man’s mastery over the environment. Not space travel, not the fifty colonized worlds that were now so haughtily independent, but the City.

My life has gotten a little more complicated than my ability to describe it. That used to be the definition of madness, now it's just continuous overload.

Strange as it may seem, wrote Richard Feynman, we understand the distribution of matter in the interior of the Sun far better than we understand the interior of the Earth.

Of all my achievements in tennis, I'm probably as proud of my record on clay courts as any of my Wimbledon, U.S. Open or French singles titles.

Being best is a false goal, you have to measure success on your own terms.

No one can take better care of you than you yourself.

For the masses who do the city's labor also keep the city's heart.

Which is worse, past or future? Neither. I will fold up my mind like a leaf and drift on this stream over the brink.