Emily Riehl is obviously one of the math cool-kids whomst we all appreciate but I do think it's funny the degree to which she displays like, the standard mathematician "having no idea what normal people know and don't know about math" thing here.
If I ever end up as a professor in a mathematics department, I'm going to make a point of telling my students they can bring a ruler to my final exams. Real analysis? You are allowed to bring a ruler. Commutative algebra? You are allowed to bring a ruler. Number theory? You are allowed to bring a ruler.


