Would you like to go to a doctor who had taken his last medical course in 1948? You have to keep changing and keep learning so that you are constantly challenging yourself, adding a few new songs to your program every chance you get. If you don't, the world will pass you by.
Harvey Mackay (1996). “Swim with the Sharks Without Being Eaten Alive: Outsell, Outmanage, Outmotivate, & Outnegotiate Your Competition”, Ballantine Books
