Fight with my wife who grew up daily shopping.
She will says "We are out of ketchup" and come home with one bottle?
WTF! "We are still out, why didn't you buy at least 2?"
I get the same thing for wanting to have 2-3 deodorants or tubes of toothpaste on hand. You don't want to be out, and it's not like it takes up much room in the cabinet.
