Persistence

"Nothing in the world can take the place of Persistence. Talent will not; nothing is more common than unsuccessful men with talent. Genius will not; unrewarded genius is almost a proverb. Education will not; the world is full of educated derelicts. Persistence and determination alone are omnipotent. The slogan 'Press On' has solved and always will solve the problems of the human race."
-Calvin Coolidge

"Many of life's failures are people who did not realize how close they were to success when they gave up."
-Thomas Edison