Peter Drucker Quotes
Every three or four years I pick a new subject. It may be Japanese art; it may be economics. Three years of study are by no means enough to master a subject but they are enough to understand it. SO for more than 60 years I have kept studying one subject at a time.
Drucker, Peter F. Management Challenges for the 21st Century. HarperBusiness, 1999, p. 163.
Peter Ferdinand Drucker was an Austrian management consultant, educator, and author, whose writings contributed to the philosophical and practical foundations of the modern business corporation. He was also a leader in the development of management education, he invented the concept known as management by objectives and self-control, and he has been described as "the founder of modern management".