A fellow of mediocre talent will remain a mediocrity, whether he travels or not; but one of superior talent (which without impiety I cannot deny that I possess) will go to seed if he always remains in the same place.

Letter to Leopold Mozart (11 September 1778), from Wolfgang Amadé Mozart by Georg Knepler (1991), trans. J. Bradford Robinson [Cambridge University Press, 1994, ISBN 0-521-58823-5], p. 12.