MARSHALL, MN—Claiming that his gruff classroom demeanor was often misunderstood, no-nonsense chemistry teacher Bill Powderly explained on Wednesday that he was only tough on his students because he gets off on exploiting his authority. “Listen folks, I’m only stern with you kids because I care [about the surge of dopamine that rushes through my brain every time I raise my voice],” said Powderly, who added that his biggest source of happiness—besides bullying adolescents for the sheer thrill—was teaching. “You don’t have to like me, but I conduct myself in this manner because [it makes me feel like an omnipotent god-king].” Powderly went on to say that one day when they became adults, his students would look back and realize he was “a [small, vindictive] man who cared.”