Not an exercise, but it’s the only intro to a prof I remember after 20 years: In freshman chem (in the late 90’s): It was a big lecture hall with stadium seating and it was early afternoon so none of the students were 100% there.

Then this middle aged man comes jogging down the center walkway/steps with a bottle in his hand. He jogs up the the lab bench at the front of the room and pours the bottle (hydrogen peroxide in retrospect) into a large beaker and all of the sudden there was a 12+ ft column of foam shooting toward the ceiling - before most of the class even new the prof had arrived. Then he turned to us an said, “we’ll learn why that happened in about 3 weeks.”

He also ended every Friday lecture with a “Boom of the Week” in which he’d explode something (larger each week) in order to make sure we didn’t skip Friday classes. Rumor has is it that, years before I got there, the last Friday’s “Boom of Week” would involve taking the class to the river and dropping a large block of magnesium metal in the water. But the college of science had asked him to stop for fear of how it affected the fish.

My highschool chem teacher’s first words were. “Ice breakers are so boring, let’s go blow stuff up!” And then imediately showed us what happened when you drop a cube of pure sodium on water.

Best fucking class I ever had.

In highschool we had a maths teacher who always did the birthday paradox as a kind of opener in the first lesson. https://en.wikipedia.org/wiki/Birthday_problem

He bet 10€, that there are 2 students with the same birthday in the classroom of (abt) 30 students. The class was allowed to work out, if they want to accept the bet, or not (exchanging birthdates was not allowed ofc).

Usually the students think, that it’s nearly impossible, and accept the bet. Little did we know, that the probability of success was around 70% for the teacher.

I like to start a major fist-fight with the first student that dares to question my god-like authority. I deadpan an old-timey “put-up-your-dukes-sonny” kind of fisticuff… they buy it 100% of the time. I like to let the student get a few in before I absolutely make mincemeat out of them.

After that, the students seem to really respect me. I have to maintain that bitter grudge with that one student the rest of the semester, though. At no point do I want them to think I’ve gone soft.