"Right, we're a trio. I'm the Boy Who Lived and Ron and Hermione wouldn't even talk to each other if it weren't for me. And Ron babysat Lockhart while I saved you. The tunnel caved in. I fought the basilisk. I nearly died from the basilisk venom. I stopped Tom Riddle. Ginny, are you feeling okay?"
Something was obviously wrong if she didn't remember him. "I've known you since you were ten!"