Characters
I've thought of an ending for my book - "And he lived happily ever after... to the end of his days."
— Bilbo · The Lord of the Rings: The Fellowship of the Ring

Behind the line May contain spoilers.
Our reading
An editorial interpretation.
Bilbo has come up with a closing line for his book. His ending is a gently comic loop, since living happily ever after until the end of his days hardly says more than that. It's a storybook flourish with a wink.
Context reviewed