Adult learning policies need to be based on an understanding of the inequalities in the uptake and benefits of learning and why adults might not participate. This needs to go beyond a mere insight in barriers that, once removed, do no longer provide a reason for adults not to participate. This article aims to delph deeper in understanding what makes adults choose to learn. It starts by applying a capability approach perspective to adult learning to evaluate whether adults have freedom to value learning and, whether they can effectively turn this freedom into learning. This conceptual framing puts certain concepts in the spotlight, namely, 'agency', 'conversion factors' and 'benefits of learning', which were further explored through a narrative literature review analysing 109 articles. This resulted in an exploration of these concepts and their interplay feeding into a conceptual model, opening new perspectives for evaluating whether adults have equal opportunities to value adult learning and turn their willingness into actual learning. This model supports future empirical studies aimed to understand participation and non-participation of adults in learning that can in turn feed policy makers with better insights and tools to develop interventions actually provide the right encouragements for adults to learn.