Positive psychology research has highlighted core factors central to living the good life during adulthood, but less is known about how childhood experiences contribute to short-term and long-term well-being. Can emotions during infancy and childhood inform later happiness and success? In the current research, I explored whether emotions during infancy and childhood predict adult well-being using data that spans from infancy into adulthood. Given that emotions are central to development across the lifespan, I expected positive emotions during infancy and childhood to predict happiness and success. In one study (N=130), I found that positive emotions, but not negative emotions, during infancy (Mage = 1.5), predicted higher childhood IQ (ages 6-8) and higher educational attainment (age 29), even after controlling for family socioeconomic status (SES). Similarly, positive emotions during infancy and adolescence (age 16) predicted age 29 life satisfaction and workplace hope. In another study, my colleagues and I found that positive emotions during childhood predicted meaning in life and social connection at age 50. Importantly, negative emotions during childhood may be adaptive over short periods of time, but positive emotions during childhood may build the foundation for living the good life by starting upward spirals of well-being.