Epigraphs are like little appetizers to the great entrée of a story. They illuminate important aspects of the story, and they get us headed in the right direction.
Oh, lucky Jim,
How I envy him.
Oh, lucky Jim.
How I envy him.
As we mention in the "What's Up With the Title?" section of our analysis, the epigraph of this book seems like an explanation of its title. But it's not all that much of an explanation. All it really says is that the person singing the song envies lucky Jim. If you look up the rest of the lyrics, though, you can see that the singer envies Jim because he gets the girl the singer also loved. But then Jim dies, and his widow marries the singer. Who's really the lucky one?
This change of fortune is what the song's really about. Why do you think Amis doesn't let us in on the last few lines of the song? Would it have been a spoiler?