Man, college art professors, not even once.
At least HS art teachers for the most part lose the ego when the go into teaching as opposed to trying to continue to make art themselves.
Most College art prof's are just failed artists, who are super arrogant about it, and they transfer all the feelings about being a failed artist into being super arrogant about how good of a teacher they are, and thus how inferior all your previous teachers must have been and thus throw away everything you knew before you met the glorious me. Like, if they knew everything and were so perfect why aren't they making a living as working artists and super famous or well respected instead?