It's Not What You Say, It's How You Say It

Playing Catchphrase with my sister's friends makes the "BABY FISH MOUTH!" scene from When Harry Met Sally seem totally plausible.

A sampling of some actual guesses that some reasonably intelligent people actually made:

"Blind mailman!"
"Clothes laboratory!"
"When someone has a heart attack it's called...?" "A heart attack!"
"This is the name of a toothpaste and also a famous painter." "Aqua-Fresh!"