This is embellished from a one-liner from Mike Brimberry.

Technical/engineering schools such as MIT and Cal Poly pride themselves on their excellence in teaching mathematical skills. They only got in trouble once in a beginning calculus course in which there was a Friday night exam. It seems that many of the students thought they knew the material so well that they drank beer all afternoon before the exam. By the bad grades on their exams, they learned that alcohol and differential calculus don’t mix. By now, most everyone knows you should never drink and derive.