Neil Gaiman, one of the great fantasy writers of our time, first started writing his comic series “The Sandman” in the nineteen-eightiess. Decades later, a TV adaptation is a huge hit on Netflix, topping the platform’s charts in countries across the globe. Gaiman talks with the producer Ngofeen Mputubwele about the powerful role that fantasy can play in helping audiences process real experiences in their lives. “You’re making things that aren’t true,” he says, “and you’re giving them to people in order to allow them to see—we hope—greater truths.” Though the Netflix début marks a major expansion of “The Sandman” ’s visibility, the series has long attracted audiences beyond ardent comic fans. Looking back to the early success of his comics, Gaiman recalls, “I would go to conventions and large, sweaty gentlemen would come over to me, grab my hands and say, ‘You brought women into my store. . . . Let me shake your hand.’ ”