Shakespeare described the terrifying beauty of the adolescent so early in its development, and so definitively and so thoroughly, that it is only slightly an exaggeration to say that he invented teenagers as we know them today. “Romeo and Juliet,” his extended study of the humiliations and glories of adolescence, is the biggest hit of all time and, unlike most of Shakespeare’s works, it has never slipped out of fashion. It has been adapted across genres and eras, into operas and ballets and musicals. The most popular brand of Cuban cigars: Romeo y Julietta. State laws that allow judges to exempt minors from statutory-rape charges are called, naturally, “Romeo and Juliet provisions.”

This shouldn’t be surprising: People just love to watch a couple of dumb kids make out and die. (And they are awfully young, these dumb Veronese kids: Shakespeare doesn’t ever tell us Romeo’s exact age but we know that Juliet is just 13.) The great French scholar Philippe Ariès concluded that for most of the Medieval period “people had no idea of what we call adolescence, and the idea was a long time taking shape.” Yet our whole modern understanding of adolescence is there to be found in this play. Shakespeare essentially created this new category of humanity, and in place of the usual mix of nostalgia and loathing with which we regard adolescents (and adolescence), Shakespeare would have us look at teenagers in a spirit of wonder. He loves his teenagers even as he paints them in all their absurdity and nastiness.

Of course, the most important feature of adolescent rebellion is that it’s doomed. In this, as well, Shakespeare was right there at the beginning. He defined what it means to be “star-cross’d.” The opposition between the adolescent and the mature orders of the world can have only two possible endings. One is comic: the teenager grows up, develops a sense of humor, marries, has kids, moves to the suburbs, gets fat and becomes boring. The other is tragic: the teenager blows up in a blaze of glory. We much prefer to live the comedy. We much prefer to watch the tragedy.

Adapted from “Flaming Youth,” a chapter in “How Shakespeare Changed Everything,” by Stephen Marche (Harper, May 2011).