And God created Woman, giving her three breasts to nurse her young.
And God spoke, saying to her, "Woman I have created thee as I see fit, but mine is no longer the only opinion in the universe (sigh). Is there anything about thee that thou would prefer differently?"
And Woman spoke, saying, "Lord, I am not made to birth whole litters, and you have given me two glorious hands, arms, feet, legs...etc.. I do not need but two breasts."
And God said, "Thou speak wisely, as I have created thee with wisdom."
There was a bolt of lightning, and it was done, and Woman stood there holding her third breast in her hand.
"That's wonderful, Lord... but what am I to do with this useless boob?" Woman asked.
And so it was that God created man.