"You don't remember it," Harry went on. "You wiped your own memory ... but you cast a spell on yourself, to stop yourself falling in love with me. But you were already in love with me, and I was already in love with you, but we were both avoiding the topic in our own ways. But we were alchemically destined to be together, and so nature decided it wasn't having any of that us-not-being-in-love nonsense. It wouldn't even let us have any say in it! So it changed your spell ... drew power from my love for you because it was just that potent a force ... to do what you wanted, and protected you from getting hurt by anything to do with me.