TITLE: How to maintain enthusiasm and joy in teaching when the material grows stale
QUESTION [51 upvotes]: I recently finished my third semester of teaching calculus to freshman college students.  This means I was drawing the same pictures, solving the same example problems, and discussing the same techniques as I had in two previous semesters.  With multiple sections per semester, review sessions, and office hours, it is possible that in one semester alone, I'll teach the same idea/say the same sentence/do the same problem 5-10 different times.
Due to all of this repetition, this last semester I felt myself growing tired of calculus.  I know that for my students, the material is new and (hopefully) interesting and exciting, but it was none of these for me, and I could feel it affect my teaching.  I would battle to maintain enthusiasm and joy for the material as I taught my students, but I often lost this battle, as is demonstrated by the following comment I received for instructor evaluations:

"Jared was a great TA who could possibly improve on enthusiasm"

I completely agree with this student, and since I hope to be able to teach mathematics for many more years than just 3 semesters, this is a problem I should begin to address now.
For teachers of mathematics, how do you maintain enthusiasm and joy in teaching the same material year after year?

REPLY [3 votes]: I've TAed for 4 semesters of calculus, though one semester of calc I, another semester of business calc, and two semesters of calc III. Every semester I've used a different textbook which has made every semester different, including the calc III semesters.
I haven't gotten bored yet, but I'm actually looking forward to it. There are a couple games I hope to play with myself.
1. Memorize your notes. Try to learn your notes completely as quickly as you can. This includes memorizing what problems that you plan to cover. Once you've memorized your examples, start tweaking the problems on the fly.
2. Use really strange analogies. I know of a professor in undergrad who was notorious for using strange examples in his differential equations class, such as talking about a differential operator acting on $e^x$ being alike a monkey throwing a coconut at a cat. Yes, very strange, but everyone remembered him because of this. I don't think you should overdo it, since it can actually detract from understanding the material correctly, but if done right it can make things more entertaining for everyone, yourself included.
3. Restrict your speech. Try to avoid using a particular word, such as "obviously", "therefore", or "now"--whatever you might frequently say. Alternatively, choose a catch-phrase per semester to use in class, perhaps something as outlandish as "golly-gee-wilikers".
4. Tell jokes. Come up with a list of jokes, math or non math related, to tell at the beginning of class, at the end of class, or exactly halfway through.
5. Think of multiple ways to do a problem. Try to think of as many ways you can do a problem, no matter how trivially different. Try to guess which path your students will take--exams are always surprising, perhaps one can take this as a challenge so as not to be surprised. Try to think of incorrect ways, including horrendously incorrect ways. Think of the points a student might get stuck at. Do a problem multiple ways, or incorrectly at first and then do it correctly in class.