Lyric discussion by dylanophoid 

Cover art for Oh Sister lyrics by Neutral Milk Hotel

I once heard in an interview with Jeff Mangum that most of the songs on "In the Aeroplane Over the Sea" were based loosely on the Book "The Sound and the Fury" by William Faulkner. That being said, I try to imagine most of the songs as if they were sung by the main character Benjy, who has a very close relationship with his older sister Caddy. If you've ever read the book and tried to view this song from the same perspective, the meaning is easy enough to see. But I'll leave that up to you.