Head over heels.

So there's the saying, head over heels. At times, an exclamative description of emotion, eg: "She was head over heels in love!" Sometimes, commentary on your lack of balance, eg: "He fell head over heels down the stairs".

Have you noticed, however, the homosapiens standing position?

Please note that in a normal, natural, standing position, the head, (A), is situated over the heels, (B). Head. Over heels. So the expression, taken literally. effectively describes the normal position for a standing or sitting human being.

So who's the idiot that thought that would emphasise a point?

Moron. Also, who's the ingenius Aussie who fixed the phrase with the expression, "Ass over tit"? See that actually makes sense. Unless the person with tits is puckering up while being fucked from behind. More on that later?!