'Happiness is never complete. Why, so often, does a surge of happiness cause the anguish of losing it? Without suffering, could we love? Without anguish and affective loss, would we need security? The world would be dull and perhaps we would not feel the pleasure of living in it'. Boris Cyrulnik. Boris Cyrulnik has written one of his most ambitious books, a text of joyful reading, which has already sold more than 300,000 copies in France, that clarifies and teaches extraordinarily useful things on such a complex subject as the enormous influence of the connection between the physical and the spiritual, or between the neurological and the psychic, in our personal development in the world. Our development as individuals and in society, the courageous decisions we make every day, the taste for exchange with other people, the shared affection, the passion we put into what we do, the eagerness to learn new things, the positive attitude we have towards existence, in short, will cause our brain to produce chemical reactions that will increase our sense of pleasure and well-being and amplify our sense of happiness. For Boris Cyrulnik, the best metaphor of existence is that of Anna Freud comparing life to a game of chess: the first moves are very important, but until the game is over, there are still some beautiful moves to make.