All of us dwellers in the universe share the property of chirality, or handedness. It keeps us from ever becoming perfectly symmetrical. We can never again be simple unisex spheres, as we were (Aristophanes assures us) in the days before there was love.
For the intense yearning which each of them has towards the other does not appear to be the desire of lover’s intercourse, but of something else which the soul of either evidently desires and cannot tell, and of which she has only a dark and doubtful presentiment. Suppose Hephaestus, with his instruments, to come to the pair who are lying side, by side and to say to them, “What do you people want of one another?” they would be unable to explain. And suppose further, that when he saw their perplexity he said: “Do you desire to be wholly one; always day and night to be in one another’s company? for if this is what you desire, I am ready to melt you into one and let you grow together, so that being two you shall become one, and while you live a common life as if you were a single man, and after your death in the world below still be one departed soul instead of two — I ask whether this is what you lovingly desire, and whether you are satisfied to attain this?” — there is not a man of them who when he heard the proposal would deny or would not acknowledge that this meeting and melting into one another, this becoming one instead of two, was the very expression of his ancient need. And the reason is that human nature was originally one and we were a whole, and the desire and pursuit of the whole is called love.
— Plato, Symposium, trans. Jowett
About that interesting characteristic there’s a new Issuu book on the wooden-looking shelf at the bottom of the screen. It’s a free download.