For decades now evolutionary biologists have argued over a conundrum. There isn't much reason for members of any species to hang around after they can no longer reproduce, because according to theory they've already fulfilled their role in life.
Some expressions, when taken to their logical conclusion, don't mean what we intend. Some are just flat-out wrong and people continue to use them...wrongly.
i gepostet a pick about the new nursery rhyme "ba ba regenbogen sheep" and heres a bbc Artikel about how schools in Britain are changing the lyrics to "ba ba black sheep" as it's apparently not politically correct