The Sorting hat in Harry Potter sorts each student into the house that corresponds to their most prominent trait. Or does it? A new fan theory posits that the trait does not have to be one the character actually possesses, but merely wants to.
Consider this: Harry Potter is sorted into Gryffindor, the house of the brave and the bold, because he asks the hat to be. The hat thought Harry was more Slytherin but he liked to think of himself as brave. Of course he rises to the occasion and displays courage, but he liked the idea of it at first. In Order of the Phoenix, after Hermione tells Dumbledore’s Army about performing a Protean Charm on the Galleons they use to communicate, one Ravenclaw asks why she isn’t in their house. She responds, “Well, the Sorting Hat did seriously consider putting me in Ravenclaw during my Sorting, but it decided on Gryffindor in the end.”
When Harry and Ron first meet her in Sorcerer’s Stone, she says, “Do either of you know what House you’ll be in? I’ve been asking around, and I hope I’m in Gryffindor, it sounds by far the best; I hear Dumbledore himself was in it, but I suppose Ravenclaw wouldn’t be too bad.”
Like Harry, Hermione was in Gryffindor both because she embodied its traits and because she wanted to be.
According to this theory, the sorting hat and the Mirror of Erised might have more in common than it seems.