On the bulletin board above my desk, I keep a handful of quotes that have taught me something, or that I hope to learn from.
Nobody asked you to write that novel.
—Jane Smiley, The Atlantic
This one's fudged a bit. It comes from a larger passage, in which Smiley explains the origin of the advice:
When I was a student at the Iowa Writers’ Workshop, I remember opening the door to my friend’s office and looking inside. Over her desk, above her typewriter, she’d tacked up a phrase: NOBODY ASKED YOU TO WRITE THAT NOVEL. I knew right away this was going to be an important idea for me. The line reminded me that writing was a voluntary activity. I could always stop. I could always go on. And since no one’s asking you do it, I’ve always seen writing as an exercise of freedom, rather than an exercise of obligation. Even when it came to be that writing was my income, it still seemed like an exercise of freedom. Yes, writing is my job—but I could always stop and do something else. Once writing becomes an exercise of freedom, it’s filled with energy.
I'd add to this, but there's nothing to add. Smiley's own takeaway from the phrase helped me to put my work into context.