Quote from Tim in Doctor in the House
Professor Garver: Hey, does everybody know what time it is?
Tim: Uh... Ph.D. time.
Professor Garver: [laughs] It's great to see you again, Tim.
Tim: And you would be?
Professor Garver: Your old philosophy teacher - Professor Garver.
Tim: Ah, yes, philosophy. "I think, therefore I am." Descartes.
Professor Garver: Good for a guy who was never in class.
Tim: Well, I thought I was there, therefore I probably was.
Professor Garver: I passed you, therefore you're lucky.