This is a small book about how to make the right choice of your betrothed and make your life happy without stupid calculations. This became possible thanks to K. Marx’s hint about what a person is. According to Plato, you choose a person, man or woman, for “soul and body.” But this is an external appearance that can be embellished, pretended, incriminated, etc., etc. According to Marx, a person is a contradictory unity of abilities and needs. In life, he creates in order to consume, and consumes in order to create. What is more in these metabolic processes? That's the question!