Purpose While research has shown reflection is a valuable part of individual learning, developing reflection habits has remained notoriously difficult, particularly for working adults. We explore whether an intervention of being able to review previous reflections will affect employee engagement in future reflection activities and raise their awareness of learning opportunities at work. Design/methodology/approach We conducted a large-scale field experiment, including 136 employees from an international bank in Europe, in which participants were asked to reflect twice a week for eight weeks. Participants were randomly assigned to either a group that was given access to their previous reflections, or a group that was not. Findings We found that individuals who were able to see their previous reflections wrote significantly more subsequent reflections than the other group. In addition, those who could see their previous reflections used more words related to learning and cognition. Practical implications Often employees may feel they are only learning when they attend formal trainings. However, this paper provides concrete guidance for how human resources management (HRM) managers can boost employees’ informal learning and awareness of the learning opportunities inherent in challenging work. Originality/value This study furthers research on using HRM interventions to facilitate informal learning activities, in particular, methods to motivate systematic reflections and raising awareness of learning opportunities. Our findings suggest that developing habits of reflection and improving awareness of learning opportunities encompasses more than simply writing reflections, but should include processing previous writings.