Two decades ago, “the boy who lived” soared across the ocean and Harry Potter and the Sorcerer’s Stone made its way into the hands of American readers for the first time. Now, twenty years later, almost everyone knows the stories, and the beloved characters from the Harry Potter series feel like old friends. Many of us know the history of J.K. Rowlings’ writing process, and how she went from single mother, struggling to make ends meet, to literary superstar. Most readers of the Harry Potter Generation can identify the books by their cover art, even by their color schemes. But what are some of the lesser known facts about the Harry Potter series, particularly the first and subsequent U.S. editions in comparison to their U.K. counterparts? In honor of the twentieth publication anniversary of Harry Potter and the Sorcerer’s Stone, here are some pieces of Harry Potter trivia that’ll help you ace even the most challenging “History of Magic” exam.