The mind is not a book, to be opened at will and examined at leisure. Thoughts are not etched on the inside of skulls, to be perused by an invader. The mind is a complex and many-layered thing.
J. K. RowlingYou - will - never - touch - our - children - again!' screamed Mrs. Weasley. Bellatrix laughed, the same exhilarated laugh her cousin Sirius had given as he toppled backwards through the veil, and suddenly Harry knew what was going to happen before it did. Molly's curse soared beneath Bellatrix's outstretched arm and hit her squarely in the chest, directly over her heart. Bellatrix's gloating smile froze, her eyes seemed to bulge: for the tiniest space of time she knew what had happened, and then she toppled, and the watching crowd roared, and Voldemort screamed.
J. K. RowlingYou are determined to hate him [Snape], Harry,” said Lupin with a faint smile. “And I understand; with James as your father, with Sirius as your godfather, you have inherited an old prejudice. By all means tell Dumbledore what you have told Arthur and me, but do not expect him to share your view of the matter; do not even expect him to be surprised by what you tell him. It might have been on Dumbledore’s orders that Severus questioned Draco.
J. K. RowlingAre you trying to weasel out of showing us any of this stuff?" said Zacharias Smith. "Here's an idea," said Ron loudly, "why don't you shut your mouth?" "Well, we've all turned up to learn from him, and now he's telling us he can't really do any of it," he said. "That's not what he said," said Fred Weasley. "Would you like us to clean out your ears for you?" inquired George, pulling a long and lethal-looking metal instrument from inside one of the Zonko's bags. "Or any part of your body, really, we're not fussy where we stick this," said Fred.
J. K. Rowling