Amnesia

"Well you see," Lupin began slowly, considering his words as he spoke, "When James got hit by the bludger and fell, he developed a form of amnesia-" "He thinks that you're his girlfriend." Black cut in. My mouth dropped open in shock. "Excuse me?" "Be quiet," Black hissed, making me realise just how loudly I had been talking. "He might hear you." "I don't care if he hears me!