Unrequited Love's A Bore

I heard the phrase "unrequited loves a boor" in Pull My Daisy. I recognized it as part of a Lorenz Hart lyric but I didn't remember the song. I couldn't understand why it was thrown in there. Nor could I figure out a lot of other parts of the movie. Anyway I did some research and discovered the connection between the lyric, Frank Sinatra and Jack Kerouac and the beats