The author begins by summarizing changes in the psychoanalytic theory of sexuality from Freud through Klein, Bion and Meltzer, that result in a clear distinction between infantile sexuality (gratification) and adult sexuality (creativity). Adult sexuality and thinking have the same origins in the introjection of a receptive and resilient bisexual (combined) object, initially the prototypal part-object pleasure between nipple and mouth; and disturbances in “fit” between mother and baby (such as, those deriving from postnatal depression), hinder realistic self-appraisal and adult sexual pleasure, which is founded on “feeling at home with oneself”. The paper then relates a baby observation to a case study of a young woman who struggles to know her “unacceptable parts” and to achieve a “rebirth of herself in identification with the baby” through an internalized breast that is “soft and receptive yet firm”.