Explaining Again

"There's no such thing as a bottomless pit!" you say again.  "If it exists on Earth, it has to have a bottom!"

"You sound like my great-nephew," the old man says.  "He always goes on about these kind of things, too.  Look down there, kid: no bottom at all."

You peer down into the darkness.  The old man puts a hand on your shoulder.

"Well, I gotta get back to the gift shop."