IN THE INTRODUCTORY paragraph of this legendary paper for Harvard Business Review, Peter Drucker writes: We live in an age of unprecedented opportunity: If you've got ambition and smarts, you can rise to the top of your chosen profession, regardless of where you started out. But with opportunity comes responsibility. Companies today aren't managing their employees' careers; knowledge workers must, effectively, be their own chief executive officers. It's up to you to carve out your place, to know when to change the course, and to keep yourself engaged and productive during a work life that may span some 50 years. To do those things well, you will need to cultivate a deep understanding of yourself - not only what your strengths and weaknesses are but also how you learn, how you work with others, what your values are, and where you can make the greatest contribution. Because only when you operate from strengths can you achieve true excellence. Marking a small foot...