Among the scant books in my tiny rented room in San Francisco, I’ve kept a spine-worn copy of Romeo and Juliet. It’s the one I read in my high school English class, the pages yellowed, the margins filled with scribbled notes. Since the play was written in the 1590s, Shakespeare’s portrayal of the nature of love—irrational, all-consuming—has been told and retold in countless movie adaptations.