The paper explores Winnicott's ideas on the detrimental effects of mothering which is too well adapted to infant needs. Winnicott claimed that such too-good mothering, when pursued beyond the baby's earliest months, led to two possible outcomes: the child would either reject the mother or would remain in a state of arrested development, merged with her. The paper follows the development of a baby girl, observed by the Bick method, and illustrates how her mother's devoted and sensitive care effectively deprived her of the development of some aspects of the sense of self and of possibilities for negotiation, concern and reparation. The baby developed a paranoid orientation and later rejected her mother after the birth of her sister. The paper also mentions the alternative outcome of a persisting state of passive merger with the mother and ends by hoping for further exploration of the means by which some sensitive, responsive parents may inadvertently ‘worse than castrate’ their children by depriving them of an autonomous sense of agency.