The primary benefit of practicing any art, whether well or badly, is that it enables one’s soul to grow.

Kurt Vonnegut, Jr. (1922-2007) American novelist, journalist

“Despite Tough Guys, Life Is Not the Only School for Real Novelists,” New York Times (1999-05-24)
    (Source)

Part of the Times "Writers on Writing" series.

In Man Without a Country, ch. 3 "Here Is a Lesson in Creative Writing" (2005), Vonnegut expanded on this:

Practicing an art, no matter how well or badly, is a way to make your soul grow, for heaven's sake. Sing in the shower. Dance to the radio. Tell stories. Write a poem to a friend, even a lousy poem. Do it as well as you possibly can. You will get an enormous reward. You will have created something.