The teacher has set the class an assignment. He stresses the importance of the particular assignment, and that no excuses will be accepted except illness (with a medical certificate) or a death in the immediate family (with a note from that member).
A smart-ass student pipes up: “What about extreme sexual exhaustion, sir?”
The class breaks up laughing, and when they settle down the teacher responds with:
“Well, Jones, I guess you’ll have to learn to write with your other hand.”