A young man wrote to Mozart and said:

Q: "Herr Mozart, I am thinking of writing symphonies. Can you give me any
   suggestions as to how to get started?"
A: "A symphony is a very complex musical form, perhaps you should begin with
   some simple lieder and work your way up to a symphony."
Q: "But Herr Mozart, you were writing symphonies when you were 8 years old."
A: "But I never asked anybody how."