Yes, I do believe that Mozart had to work extremely hard to write his music; infact, it has been documented that he was obbsessed with his music, and refining his craft. I am sorry but I have to correct you, Mozart was not self-taught. His father is/was one of the best known composers of his time and created some terrific works. Mozart was not born a genius (prodigy) he was created as so through his unique upbringing and passion to learn. I agree that everyone is unique and has different gifts, but this is largley shaped by experiences (or lack there of) not genetics.