He was so upset that he sat straight up in bed. Tereza was breathing deeply beside him. The woman in the dream, he thought, was unlike any he had ever met. The woman he felt he knew most intimately of all had turned out to be a woman he did not even know. And yet she was the one he had always longed for. If a personal paradise were ever to exist for him, then in that paradise he would have to live by her side. The woman from his dream was the ‘Es muss sein!’ of his love.
He suddenly recalled the famous myth from Plato’s Symposium: people were hermaphrodites until God split them in two, and now all the halves wander the world over seeking one another. Love is the longing for the half of ourselves we have lost.
Let us suppose that such is the case, that somewhere in the world each of us has a partner who once formed part of our body. Tomas’s other part is the young woman he dreamed about. The trouble is, man does not find the other part of himself. Instead, he is sent a Tereza in a bulrush basket. But what happens if he nevertheless later meets the one who was meant for him, the other part of himself? Whom is he to prefer? The woman from the bulrush basket or the woman from Plato’s myth?
He tried to picture himself living in an ideal world with the young woman from his dream. He sees Tereza walking past the open windows of their ideal house. She is alone and stops to look in at him with an infinitely sad expression in her eyes. He cannot withstand her glance. Again, he feels her pain in his own heart. Again, he falls prey to compassion and sinks deep into her soul. He leaps out of the window, but she tells him bitterly to stay where he feels happy, making those abrupt, angular movements that so annoyed and displeased him. He grabs her nervous hands and presses them between his own to calm them. And he knows that time and again he will abandon the house of his happiness, time and again abandon his paradise and the woman from his dreams and betray the ‘Es muss sein!’ of his love to go off with Tereza, the woman born of six laughable fortuities.
– Milan Kundera, The Unbearable Lightness of Being (trans. not mentioned)