A few moments ago I happened to notice a small pencil sharpener, the kind with a steel blade set at angle, in my tray of miscellany. I was struck by an urge to sharpen a wooden pencil. I wanted to feel the blade cutting through the incense cedar fibers. I felt this need physically, starting in my front shoulders and forearms, to make some wooden shape with a smooth cut of a perfectly sharpened chisel or knife or plane or handsaw – a throwback to my carpentry days.
In the same way, as I watched our senior math majors’ capstone talks, I felt the need to understand some small area of mathematics and explain it to somebody as they were doing. This is, of course, part of my job, what I do, a fun part. The emotional imperative to explain and explain well might account for whatever quality my lectures have and comes from the depths of my being.