Describe symbolism in In His Own Write by John Lennon

There are times when Lennon doesn't seem to mean for the reader to glean anything from his writing but humor, and yet, there are other times when he seems to be trying to convey a mirrored reflection to the real world, and the way that things don't always make sense. Frank, foe instance, is a character that Lennon uses to depict someone who would be considered "average" by the world's standards and a smart man. He goes insane and kills his wife because he gained a few pounds. While this is a stretch of the events that would occur, Lennon uses this same type of symbolism several times in his writings with death as a focal point.