"It is probably the question I get asked most often by students: how did you achieve what you did? There is an urgency to the question and more than a little self-interest. If I can figure out how he made it, the student reasons, then maybe I will know how to chart my own path. It was always difficult to provide a simple answer to a long and complex journey. So I often leave the inquiring student with a pointer here or a caution there. Never enough...