Today's wealthy societies are more fluid, varied and complex than they were just a few decades ago. As a consequence, what were "vocational choices" at the beginning of the 20th century now appear as "life designing issues". In this context, contemporary research stresses the plurality and relative malleability of human subjects as well as their ability to take reflexive stances on their current and past experiences. Fitting in such an epistemology, a self-constructing model is proposed as a basis for a life designing counseling interview. This model describes self-identity as a dynamic system of (past, present and expected) subjective identity forms (SIF), the synthesis and dynamism of which originate in a tension between two kinds of reflexivity. Counseling interviews with emerging adults show that the elicitation of some expected SIF allows them to re-read their current and past experiences from such a perspective and constitutes a compelling incentive to act. (Contains 1 table and 1 figure.)