A recurring theme is that formal schooling wasn't helpful; in fact, formal schooling is often identified as a hurdle to their lives as writers...
See this excellent article from The Guardian (U.K.) that brings this issue to light:
Roddy Doyle: the joy of teaching children to write
An excerpt from the article:
The centre, which takes its name from a common Dublin expression meaning words used to advance an argument, was also partly a response to a lack of creativity in Doyle's own education. The Christian Brothers who ran his secondary school gave him no encouragement to write fiction. For years, Doyle simply assumed he didn't have the talent or discipline to put pen to paper. Today's children, he says, deserve better.(b) Somewhat related, are our schools building equity...or perpetuating inequity, particularly higher education?
"When I was growing up, the exam system didn't allow you to write fiction, so you never did," he says. "There was an absence of thought [about creative writing] which seems daft in retrospect." Doyle didn't start writing regularly until he became an English and geography teacher in his 20s. "I didn't have the discipline until then."
Consider A Smug Education? (New York Times, March 8, 2012); an excerpt:
Consider the fact that SAT scores (a big factor in college admissions) correlate closely with family wealth. The total average SAT score of students from families earning more than $100,000 per year is more than 100 points higher than for students in the income range of $50,000 to $60,000. Or consider that a mere 3 percent of students in the top 150 colleges, as defined by The Chronicle of Higher Education, come from families in the bottom income quartile of American society. Only a very dogmatic Social Darwinist would conclude from these facts that intelligence closely tracks how much money one’s parents make. A better explanation is that students from affluent families have many advantages — test-prep tutors, high schools with good college counseling, parents with college savvy and so on.
Yet once the beneficiaries arrive at college, what do they learn about themselves? It’s a good bet that the dean or president will greet them with congratulations for being the best and brightest ever to walk through the gates. A few years ago, the critic and essayist William Deresiewicz, who went to Columbia and taught at Yale, wrote that his Ivy education taught him to believe that those who didn’t attend “an Ivy League or equivalent school” were “beneath” him. The writer Walter Kirn recalled that at Princeton he learned to “rise to almost every challenge ... except, perhaps, the challenge of real self-knowledge.” In my experience, a great many students at top colleges are wonderful young people whose idealism matches their intelligence. Yet the charge that elite college culture encourages smugness and self-satisfaction contains, like Mr. Santorum’s outburst, a germ of truth.