The spotlight is on those who are ageing today, observing and supporting an ageing process that is described as ‘capable’ or ‘healthy’. But they are also urged to ‘behave’: not to become dissidents from the socio-economic and cultural ideals of autonomy, independence and control that today set activity as a model of normality; not to become a burden on society because of the social cost of caring for dependency; not to become a burden on their children and grandchildren. These injunctions are a paradigmatic concern of our time, which cannot be explained by biological and social reality alone. On the basis of encounters with men and women confronted with the need for care in old age, we propose to examine the ways in which subjects appropriate what constitutes their dependency and the help they receive, the ways in which they organise their behaviour and the psychic work they mobilise. From our perspective, dependency appears both as a dynamic process and as an outcome of this process, which is always liable to be reshaped and destabilised, particularly during the transitions that accompany the life course and mark biographical and existential thresholds.