This paper studies the evolution of life satisfaction over the life course in Germany. It clarifies the causal interpretation of the econometric model by discussing the choice of control variables and the underidentification between age, cohort and time effects. The empirical part analyzes the distribution of life satisfaction over the life course at the aggregated, subgroup and individual level. To the findings: On average, life satisfaction is mildly decreasing up to age 55 followed by a hump shape with a maximum at 70. The analysis at the lower levels suggests that people differ in their life satisfaction trends, whereas the hump shape after age 55 is robust. No important differences between men and women are found. In contrast, education groups differ in their trends: highly educated people become happier over the life cycle, where life satisfaction decreases for less-educated people.