This article deals with the situation where the passage to the adult life fails or the adolescence does not end or is prolonged. First, how adolescence ends and what it really means is discussed. Nowadays, it can be stated that due to the extension of the duration of studies and some socio-economic conditions such as unemployment, the passage to adulthood has become more complicated. However, the article focuses on the psychic dimension of that process. Thus, first of all, a short summary about the psychic work on adolescence is given. Then, the main subject is discussed according to the work of François Ladame, who has put this concept beyond ages in his book Les Eternels Adolescents. The importance of the constitution of identity through the dialectic between the individual and collective and of the risk of deception involved in the object choice for the passage to the adulthood is emphasised. Finally, a French comedy movie Tanguy, whose main character has become the prototype of the never-ending adolescence, is discussed.