Teachers have been instrumental to Oprah's Book Club 2.0 author Ayana Mathis. The "Twelve Tribes of Hattie" writer credits her mentor, Pulitzer Prize-winner Marilynne Robinson, with giving her three invaluable pieces of advice about writing. In this video, Ayana shares those top lessons -- which she says made her grow as a writer -- with Oprah. Oprah's interview with Ayana Mathis airs on "Super Soul Sunday" on Feb. 3 at 11 a.m. ET on OWN.