Dunno, maybe made up?
and to continue on the topic:
"A college teacher reminds her class of tomorrow's final exam. "Now class, I won't tolerate any excuses for you not being here tomorrow. I might consider a nuclear attack or a serious personal injury or illness, or a death in your immediate family, but that's it, no other excuses whatsoever!"
A smart ass guy in the back of the room raised his hand and asked, "What would you say if tomorrow I said I was suffering from complete and utter sexual exhaustion?" The entire class is reduced to laughter and snickering.
When silence is restored, the teacher smiles knowingly at the student, shakes her head and sweetly says "Well, I guess you'd have to write the exam with your other hand."