The arrival fallacy is a bias in affective forecasting where individuals mispredict the intensity and duration of happiness obtained from achieving certain goals or milestones. People often believe that reaching a specific outcome, such as getting a promotion or earning a certain amount of money, will bring them long-lasting happiness. However, research shows that these expectations are usually inaccurate. Affective forecasting errors lead to disappointment because the actual happiness experienced is not as great or as long-lasting as anticipated. This bias is not limited to individuals with average incomes but also affects wealthy individuals who continue to chase higher financial milestones, believing that each new level of wealth will bring them the happiness they seek. Even when previous goals have not brought the expected happiness, individuals rarely question their assumptions and instead continue to pursue further achievements. This bias highlights the misconception that material success alone will lead to sustained happiness, and it emphasizes the importance of understanding the true factors that contribute to long-term well-being.