Teaching as performing

Today I taught in three different classes (one and a half hours each) back-to-back.and followed it by a couple of significant administrative meetings. Although we all know that standing up and performing is tiring, and teaching is a kind of performance, I was a bit surprised by just how mentally draining it was to do all that teaching without a break, and by the way in which that dysfunction was manifested (which was via a more boring presentation).

Usually after a lecture I am a bit exhilarated, and maybe even after two back-to-back lectures my eventual fatigue is balanced by the thrill of giving the lecture, but three in a low is just too much. Personally I like taking questions, reflecting on new ideas and improvising in class, but by the end of the third lecture I was doing things a lot more "by the book" than usual, in addition to being pretty hoarse. I am sure this kind of reaction depends on the material and today I gave one lecture in a class that was new to me, and another in a class populated only by PhD students dealing with a fairly recent research result.

Despite the fatigue though, there is a great sense of satisfaction one gets from delivering classroom material, assuming it goes at least moderately well.