In this contribution, we mobilize the interdisciplinary life course paradigm to consider the processes through which individual heterogeneity in active ageing and wellbeing is constructed all along life, from the cradle to old age. Considering altogether historical, family and individual times, the life course perspective has been developed in sociology, (lifespan) psychology and epidemiology, and has framed many important studies during the last four decades. The theory of cumulative disadvantage is for sure the most popular in social sciences, explaining how little inter-individual differences early in life expand all along life to reach maximal amplitude among the “young old” (before the selection by differential mortality at very old age). In lifespan psychology, the theory of cognitive reserve (educational level being a proxy) and its continuation, the theory of use or disuse (of cognition during adult life) have more or less the same explanatory power, cognition being a decisive precondition for active ageing and quality of life in old age. However, in spite of the success of those theoretical bodies, a prominent figure in the field, Glen Elder, recently observed that there is surprisingly little evidence for cumulative processes and that a wide variety of model specifications remain completely untested. This finding makes even more important a critical review of the literature which will summarize several robust evidences, but also discuss contradictory results and suggest promising research tracks. This exercise will have to consider the life course construction of inequalities in the distribution of objective resources older adults have (or not) “to live the life they own value” (to quote A. Sen, 2001). But it will also be crucial to consider the subjective component that is inherent to the understanding of well-being.