Humans are notoriously bad at predicting their future happiness. A new study published in Psychological Science suggests that part of the reason for these mispredictions lies in failing to recognize the key role played by one’s own personality when determining future emotional reactions. The new evidence comes from Jordi Quoidbach, a psychological scientist at the University of Liege, Belgium who found that our natural sunny or negative dispositions might be a more powerful predictor of future happiness than any specific event. They also discovered that most of us ignore our own personalities when we think about what lies ahead—and thus miscalculate our future feelings.