Shel Silverstein uses symbolism in his poem "Rain" to symbolize how rain messed up his head. In my interpretation of this poem, rain appears to be a symbol. It could symbolize many things that could mess with one's head. The poem begins with the story of how the rain got in his head and then continues on with how the rain messed up his head. It is a very intriguing poem that is able to symbolize many things.