It was just something we covered in a semantics course at the University of Wisconsin.
Why would I make up a retroactive story to 'cover my butt' when I was not the one who said it?
Found this though..
Well, I didn't think you made it up
But even the Dictionary.com post seems to say "it happened, we don't know why...hey, let's be kind and assume they did it for a reason!"
I'm not so kind