So Long, Farewell was a song from the Earth musical and movie The Sound of Music.
When Maldis was taunting John Crichton, he said "Fear makes me stronger. Fear and the terror of helplessness. These are a few of my favorite things." When Crichton heard this, he asked "Oh, could you do that farewell good-bye song the kids sing? It's one of my favorites." ("Picture If You Will")