Sometimes in life we get so caught up in what would make our first world lives even more amazing. We want wealth and food and happiness and love for ourselves, and then once we're satisfied we just sit and do nothing. Esmerelda's song is full ironic imagery, but the best part is when she stands in the light of the rose window, a priceless work of historical art, and the beauty of her compassionate heart makes you just hate that the window even exists and that people give it so much importance.
Not all heroes wear capes. Nothing i can say can add to what this scene conveys.
I'm as guilty as the rest of you. I don't love my fellow humans as much as I should. Lets all do better ok?