Any woman who goes back to school at the age of 68 for a degree that seems to be, on the face of it, entirely worthless is necessarily living by faith. When I returned to Columbia University’s School of the Arts to secure an M.F.A. in creative nonfiction, I know I sure was. Trusting that the universe would provide, that the usual impediments would simply melt away, I, the faithful one, plunged in, seeking a way…