A large literature in behavioral and social sciences has found that human wellbeing follows a U-shape over age. Some theories have assumed that the U-shape is caused by unmet expectations that are felt painfully in midlife but beneficially abandoned and experienced with less regret during old age. In a unique panel of 132,609 life satisfaction expectations matched to subsequent realizations, I find people to err systematically in predicting their life satisfaction over the life cycle. They expect incorrectly increases in young adulthood and decreases during old age. These errors are large, ranging from 9.8% at age 21 to -4.5% at age 68, they are stable over time and observed across socio-economic groups. These findings support theories that unmet expectations drive the age U-shape in wellbeing.