Right guys...cavemen probably drank water or nothing at all. You REALLY think they made beer? ha! A more realistic name for this type of brewing would be more like Medieval brewing.
"Caveman no malt"? "Caveman no Braggot!"
On a related note, I've heard that about the rule of thumg also. I also heard it came from the law prohibiting men from beating their wives with a stick any thicker than their thumb.