Apparently, we are all victims of a terrible conspiracy. Yes, that's right, we've been taught the wrong melody to Silent Night! I had heard the "real" last melody line of the song before, when sung in German ("Stille Nacht! Heilige Nacht!"). But it never registered that there was a story behind this two-note difference, until I ran across this slightly bizarre account of why we sing a different version of the melody than the Germans and Austrians do. Wierd...