Theisen’s last bout

Jet Miller '24, Staff Writer

After 33 years of teaching, (29 years at South), chemistry teacher John Theisen is calling it quits. For all who know him, Theisen is one of the most admired and respected teachers at South, not only for his effective teaching style, but also because of his commitment to the students. Although he looks forward to the extra time he’ll have in retirement, Theisen says he will miss teaching, a process he has come to master after decades of practice.
“(I’ll miss) watching people learn,” Theisen said. “It’s referred to as (an) epiphany. The light bulb, when I find that I’ve been able to take a reasonably complicated situation like determining the pH at the equivalence point of a titration of a weak acid (with) a strong base and people understand what I’m talking about. That’s fun.”Beyond fun, Theisen’s teaching has had real-world impacts, with countless students who have gone on to pursue careers as doctors, scientists and rocket engineers.

Mr. Theisen’s first school photo. (Jet Miller ’24)

“Every time SpaceX launches, I have two or three former students involved with building that space ship,” Theisen said.

Theisen’s ability to teach in an effective way is also reflected in the AP scores of his previous classes, which, historically, have been remarkably high.

“Last year was the last year I did AP (Chemistry), and my lowest scores were fours,” Theisen said. “To see the students go through the pandemic and still keep the class average around a four on the test, that was an accomplishment for them more than for me.”

Mr. Theisen’s last school photo as he heads into retirement. (Jet Miller ’24)

As for retirement, Theisen hesitates to make any decisive plans as of right now, opting to decide when he gets there.

“I think I’ve decided to not decide for a little while,” Theisen said. “There’s a saying: ‘You don’t know what you don’t know,’ and there’s a whole lot I don’t know, so I’m gonna just wait and try to know some of it.”

At the tail-end of a decades-long career, Theisen’s parting words are short but compelling:

“Don’t forget (that) knowledge is power,” Theisen said. “The people who say you don’t need to know; that you can just look it up, don’t want you to have that power, and you have to ask yourself why.”