talking about infinity

Nonmathematical people sometimes ask me,

"You know math, huh? Tell me something I've always wondered, What is infinity divided by infinity?"

I can only reply,

"The words you just uttered do not make sense. That was not a mathematical sentence. You spoke of 'infinity' as if it were a number. It's not. You may as well ask, 'What is truth divided by beauty?' I have no clue. I only know how to divide numbers. 'Infinity', ' truth', 'beauty'--those are not numbers."

-- John Derbyshire (Prime Obsession)