I think the author confuses experts at performing particular tasks and experts for some field of knowledge. And then goes on to reiterate the age old wisdom th

I think the author confuses experts at performing particular tasks and experts for some field of knowledge. And then goes on to reiterate the age old wisdom that you need to practice, and especially the fundamentals, to gain expert skills. To become expert at either teaching a skill or a subject matter, or even advance the field, I think the most important activity is to find out and understand what and how they are doing and thinking. Standing on the shoulders of Giants is a good first step even if just to survey where to leap next.