Source:
Peter Hay, Book of Business Anecdotes, p. 108
Legendary salesman Frank H. Davis often likened the salesman's lot to that of a veteran schoolteacher who storms into a principal's office to complain about the promotion of a junior staffer. "I," she cries, "have had twenty-five years of experience." "No, my dear," the principal patiently replies, "you have merely had one year of experience 25 times."