Another Expression I Hate....

All this talk about love...what's with the saying 'head over heels in love'? Isn't our head already over our heels? At least mine is if you look at me. I do know I'm far from the first person to draw attention to this fact. Anyhow. Is it that one 'falls' head over heels - like tumbles forward, gymnastics style? But still, I don't know that the head is going over the heels - maybe more like going under the heels. I guess I get it, but I don't like the expression.

Anyone out there like this expression, or know the origin?