...then he heard the elderly lady say, "concrete, cement. It's all the same to me."
"Just yesterday," Bob said, "I had that discussion with the Missus. When you add water and aggregate to cement you get concrete.
"Whatever," the lady said.
"Exactly," said the Missus.
Then the old guy to his left asked, "You've been married how long, and you don't know you are wasting your breath?"