"But does everyone know it, though?" Hermione asked, shrewdly. "As famous as your story is, Harry, you were never explicit about that part of it, about your early life. Even I didn’t know the whole of it until I went into your mind. If you kept that from me ... and I assume Ron, too ... who else might be expected to know about it? Sirius and Dumbledore maybe, but both are dead. I think this may be your biggest secret, Harry."