He chose the boy he thought most likely to be a danger to him," said Dumbledore. And notice this, Harry. He chose, not the pureblood (which, according to his creed, is the only kind of wizard worth being or knowing), but the half-blood, like himself. He saw himself in you before he had ever seen you, and in marking you with that scar, he did not kill you, as he intended, but gave you powers, and a future, which have fitted you to escape him not once, but four times so far — something that neither your parents, nor Neville’s parents, ever achieved.
