"Since I was in the company of an intellectual, I will quote from Plato. According to him, at the beginning of creation, men and women were not as they are now; there was just one being, who was rather short, with a body and a neck, but his head had two faces, looking in different directions. It was as if two creatures had been glued back to back, with two sets of sex organs, four legs and four arms.
The Greek gods, however, were jealous, because this creature with four arms could work harder; with its two faces, it was always vigilant and could not be taken by surprise; and its four legs meant that it could stand or walk for long periods at a time without tiring. Even more dangerous was the fact that the creature had two different sets of sex organs and so needed no one els in order to continue reproducing.
Zeus, the supreme lord of Olympus, said: 'I have a plan to make these mortals lose some of their strength.'
And he cut the creature in two with a lightning bolt, thus creating man and woman. This greatly increased the population of the world, and, at the same time, disoriented and weakened its inhabitants, because now they had to search for their lost half and embrace it and, in that embrace, regain their former strength, their ability to avoid betrayal and the stamina to walk for long periods of time and to withstand had work. That embrace in which the two bodies re-fuse to become one again is what we call sex".
Script from the book "Eleven Minutes" by Paulo Coelho.