This is precisely why I being a teacher! Young people are so infernally convinced that they are absolutely right about everything. Has it not occurred to you, my poor puffed-up poppinjay, that there might be an excellent reason why the Headmaster of Hogwarts is not confiding every tiny detail of his plans to you? Have you never paused, while feeling hard-done-by, to note that following Dumbledore's orders has never yet led you into harm? No. No, like all young people, you are quite sure that you alone feel and think, you alone recognise danger, you alone are the only one clever enough to realise what the Dark Lord may be planning.