I’ve just started my 45th year teaching at Berklee, and, with 50 years in front of classrooms (earlier teaching stints at Indiana University and the University of Notre Dame) someone might ask, “Isn’t that enough? When are you going to retire?” For me, retirement means stopping doing something you’d rather not do, in order to do something you’d rather do. Using that definition, I’ve been retired for nearly 50 years. It’s the thing I’d rather be doing, the thing I have a passion for. As an undergraduate philosophy major at the University of Minnesota, I took a Humanities course in the great novels. Reading Voltaire’s Candide, I found a principle that’s informed much of my work and certainly my attitudes towards both my professional and personal life. After an entire novel of trouble and misadventures, Candide and the philosopher Pangloss …