This is a favorite quote:
"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."
- Calvin Coolidge
You have to know some of the untalented millionaires that I know whose greatest talent is persistence.