Happy people remember more good events than actually happened, and they forget more of the bad events. Depressed people, in contrast, are accurate about both.

I used to think that the topic of positive psychology was happiness, that the gold standard for measuring happiness was life satisfaction, and that the goal of positive psychology was to increase life satisfaction. I now think that the topic of positive psychology is well-being, that the gold standard for measuring well-being is flourishing, and that the goal of positive psychology is to increase flourishing. This theory, which I call well-being theory, is very different from authentic happiness theory, and the difference requires explanation.

Expectation always introduces an element of bias, because it anticipates outcomes without waiting to see what actually happens. However, if expectations are consistently modified in the face of experience in a (*)-like or Bayesian manner, then over time, the influence of initial expectations will tend to diminish as new experiences “tune” expectations to actual frequencies through the reduction of prediction error. As experience grows in magnitude and diversity, Bayesians point out, initial expectations tend to “wash out,” and individuals who began from different starting assumptions, but encountered similar experience, will tend to converge in their expectations. And importantly, they will tend to converge on the actual “natural statistics” of their environment