Why did Kurt Vonnegut Jr write Harrison Bergeron?

Harrison was extraordinary his entire life, but, in my opinion, when he was fourteen the "Handicapper General" realized that none of the handicaps available would work on him. That is why Harrison was imprisoned when he was fourteen. As far as why Vonnegut chose the age of fourteen, probably due to that is when most people start to discover who they are and what they want to become. It could also be relevent to the author's life.