One day our professor was discussing a particularly complicated concept. A pre-med student rudely interrupted to ask "Why do we have to study this stuff?"

"To save lives," the professor responded and continued with the lecture.

A few minutes later the same student spoke up again. "So, how does physics save lives?" he persisted.

"It keeps the ignoramuses out of medical school," replied the professor.

(from Mikey's Funnies)