The importance of milk in human culture is attested to by the numerous expressions embedded in our languages, for example, "the milk of human kindness", the expression "there's no use crying over spilt milk" (which means don't "be unhappy about what cannot be undone"), "don't milk the ram" (this means "to do or attempt something futile") and "Why buy a cow when you can get milk for free?" (which means "why pay for something that you can get for free otherwise").