The one line that summarizes the series, what it has contributed to our childhoods, books and films alike. The one line that reminded a snobby, blockbuster-jaded cinephile of the little kid still awake at 2AM, desperate to finish that chapter. The one line that brought the prick to tears and put a smile on his face. "Of course it's all happening in your head, Harry. Why should that mean it isn't real?"