"Painting. Sculpture. Composing. Singing. Acting. The playing of a musical instrument. Writing. Enough books have been written on these seven subjects alone to sink a fleet of luxury liners. And the only thing we seem to be able to agree upon about them is this: that those who practise these arts honestly would continue to practise them even if they were not paid for their efforts; even if their efforts were criticized or even reviled; even on pain of imprisonment or death."

He struck gold, of course, but note the sentiment he expressed. By his own admission, had he never been paid for it, he would have kept writing anyway, because that's what he does. And when he was starting he had other jobs -- and a family to support -- and really struggled with money, but kept going anyway.