Attempts to measure learning are hampered by the tendency to use precise and objective information. As a result, an important part of what people learn remains below surface. In this paper we depart from this tradition. Our approach is to measure learning with subjective questions which capture the theoretical concepts. We distinguish between the time used to learn and outcomes. We also distinguish between people performing certain tasks aimed at learning and learning as a side-product of productive activities. This new approach provides an interesting picture of the importance of informal learning: 94% of learning at work is informal, each year of experience is worth six months of schooling. Although people learn less when they become older, people at work continue learning until retirement, while people who are not in school or work part time lose skills and knowledge from age 57 onwards.