This article is edited from a story shared exclusively with members of The Masthead, the membership program from The Atlantic (find out more). In part one, we explore why adults gravitate towards books written for children and teenagers. In part two, we hear from best-selling YA author John Green about his latest protagonist and the stigma surrounding mental illness. Young-adult literature typically centers on teenagers. But while the publishing industry markets these books primarily to young adults, that’s not always who reads them. Approximately 55 percent of today’s YA readers are adults. To find out why, I consulted the president of a young-adult publishing imprint, a professor of young-adult literature, a few Masthead members who love YA, and Green himself. Here’s what they said. These books are about coming of age, and we’re still coming of age. “What all these YA novels share is a universal coming of age experience,” Jennifer Loja, president of Penguin Young Readers, wrote to me in an email. The bildungsroman—the original term for a coming-of-age story—dates back to 17th century Germany, when Johann Wolfgang Goethe and his contemporaries began writing stories about young protagonists, progressing on a journey toward maturity. “To come of age is perhaps the most common ground there could be among readers,” said Virginia Zimmerman, professor of English literature at Bucknell University. “Adults recognize it as something they’ve been through, but they also recognize it as something of a fantasy. It suggests some sort of stable existence. And as adults, we know that we continue to change, continue to come of age.” The intensity of the first time. Green said teenage characters give him an opportunity to articulate a completely different kind of emotion. “Teenagers have a reputation for being jaded and cynical, but in fact I find them wondrously lacking in cynicism and wondrously earnest in their un-ironized emotional experience.” A lot of that stems, he said, from experiencing everything for the first time. Your first kiss, your first slow dance, your first time driving a car, your first failure. “The first time has an intensity to it that the second time