Organic chemistry professor's misconception about protons in NMR

[Mandelbroth]

I can't remember anything about the context anymore, but I once drew a diagram on the board, realized I basically just drew a giant penis, and decided to cover my tracks by saying "actually I don't think we need a picture for this" and quickly erasing it

When I was in eighth grade, I attempted to demonstrate the idea of the Mandelbrot set (Fractal geometry, in my opinion at the time, was "not covered extensively enough.") to my geometry class. I quickly realized that a hand drawn version looks a lot like a hairy penis. It was certainly an awkward moment.

My stat mech teacher didn't know the names of the Greek letters - so he called xi "the wiggly worm"!

I love calligraphy, so I can't quite relate to this, but...this.

It wasn't a college prof, but I once had a biology teacher in OK insist that Turtles are amphibians. She even sent me to the principal's office for arguing. My dad proudly took me home that night and wrote quite the lengthy letter, and had his brother (a professor of biology) send her a letter also.

You should be proud. It's rather obvious that a turtle is a mammal.