More thoughts from George Carlin:
"If it's art, it should mature. Entertainers and artists — although I am a little of each — are not the same. Entertainers are fairly static. An artist is generally in motion, on some sort of a journey, if you'll pardon the expression, some sort of a path to something that they can't really define. So they're never really satisfied. They're always looking for the next thing inside themselves or the next thing outside to spark them. And I think the artist in me woke up about halfway through the game and said, Oh, this is what we're doing. It's not just showing up and pleasing people, it's getting some stuff out of your head and off your chest, out of your heart, whatever you want to call it"
"... artists are never finished, they're never satisfied. The great cellist Pablo Cassal, from the last century, he was a past master of his instrument, he was the virtuoso of the cello. In his 90s he still appeared at the occasional recital. But more to the point, he practiced every day for three hours. And someone close to him asked him one time, "Maestro, at your advanced age, you're already a past master of this instrument, you're 93 or 94, why do you practice three hours a day?" And he says, "Well, I'm beginning to notice some improvement."