To me success means effectiveness in the world, that I am able to carry my ideas and values into the world - that I am able to change it in positive ways.
And if you're a golfer and you watch a golf film and Matt Damon swing, and it's not great, then you're not going to believe in the golf story, you're not going to believe in the rest of the film. That's the whole movie, so if that swing looks like crap, the movie's crap.
He's a world-famous name to people who care about his music, but there are many people who have never heard of George Gershwin and those numbers increase.