Action without intelligence is a form of insanity, but intelligence without action is the greatest form of stupidity in the world.

If you're doing something the same way you have been doing it for ten years, the chances are you are doing it wrong.

A problem well stated is a problem half-solved.

Failures, repeated failures, are sign-posts on the road to achievement. The only time you don't want to fail is the last time you try something (and it works).

Do not bring me your successes; they weaken me. Bring me your problems; they strengthen me.

I could do nothing without my problems; they toughen my mind. In fact, I tell my assistants not to bring me their successes for they weaken me, but rather to bring me their problems, for they strengthen me.

The world hates change, yet it is the only thing that has brought progress.