Thinking is the hardest work there is, which is probably the reason so few engage in it.

The major reason for setting a goal is for what it makes of you to accomplish it. What it makes of you will always be the far greater value than what you get.

Let others lead small lives, but not you. Let others argue over small things, but not you. Let others cry over small hurts, but not you. Let others leave their future in someone else's hands, but not you.

Your most unhappy customers are your greatest source of learning.

Because ideas have to be original only with regard to their adaptation to the problem at hand, I am always extremely interested in how others have used them...

I've always found the second book in a series is the hardest to write.

Speak softly and carry a big stick; you will go far.

Genius is eternal patience.

If you are five minutes early, you are already ten minutes late.

Few things are impossible to diligence and skill. Great works are performed not by strength, but perseverance.

I'm a greater believer in luck, and I find the harder I work the more I have of it

All my life I've had one dream, to achieve my many goals.

Results! Why, man, I have gotten a lot of results. I know several thousand things that won't work.

Hell, there are no rules here - we're trying to accomplish something.

Whenever you are asked if you can do a job, tell 'em, 'Certainly I can!' Then get busy and find out how to do it.

To invent, you need a good imagination and a pile of junk.

The difference between a successful person and others is not a lack of strength, not a lack of knowledge, but rather a lack in will.

Opportunity is missed by most people because it is dressed in overalls and looks like work.

When things go wrong don't go with them

All achievement, all earned riches, have their beginning in an idea.

One can have no smaller or greater mastery than mastery of oneself.