Though originally a fanatic for Bathilda Bagshots Hogwarts: A History, Hermione Granger eventually took umbrage with the book. And for good reason.

Granger didnt appreciate how the book neglected to mention Hogwarts use of House Elves. We second that, but were more perturbed about other omissions. For instance, what about the theory that Ron Weasley is a time-traveling Albus Dumbledore , or that Voldemort doesnt have hair because he doesnt want anyone to create a Polyjuice Potion of him?

No bother. In honor of 20 years since the Harry Potter books, and 15 years since the film Harry Potter and the Chamber of Secrets, weve gathered the most magical theories together in one place.

There are more theories than flavors of Bertie Botts Every Flavour Beans, but here are the ones you should know based on popularity and evidence.

We even brought in our sorting hat to put them into three categories: The Chosen Ones, Keepers and Simply Riddikulus. (Theres not a terrible theory alive that didnt wind up in Riddikulus.)

The Chosen Ones

These are the theories who lived.