From Seth Godin:
Columbus was a failure. He failed when he joined in the attempt to conqure the Kingdom of Naples. He was captured by Portuguese ships as he escorted an armed convoy. He was wounded. And he never did get to India. The fact that he didn't give up and become a shopkeeper after this rought start was critical to his success.
Columbus didn't do his research carefully, reinforcing his optimism. He thought that calculations of the size of the Earth were in Italian miles, not in the longer Arabic miles. The correct calculations would have 'proven' he should never have left.
Ultimately, in death, Columbus became a brand, a story bigger than his own facts. Buried in Spain, moved to Santo Domingo, then to Havana and then back to Spain. Namesake of the Knights of Columbus. Statues and streets and even cities. In many ways considered the "first American," demonstrating vision, persistence, insight, brilliance, bravery and world changing paradigm shifting... almost none of it true, of course.