However, optimism is highly valued, socially and in the market; people and firms reward the providers of dangerously misleading information more than they reward truth tellers. One of the lessons of the financial crisis that led to the Great Recession is that there are periods in which competition, among experts and among organizations, creates powerful forces that favor a collective blindness to risk and uncertainty.

I used to hold a unitary view, in which I proposed that only experienced happiness matters, and that life satisfaction is a fallible estimate of true happiness.

I'm not a great believer in self-help.

Often, the most enjoyable part of an activity is the anticipation.

Many people will admit that they made a mistake [putting money in dot-coms or telecoms at their peak] But that doesn’t mean that they’ve changed their mind about anything in particular. It doesn’t mean that they are now able to avoid that mistake.

To know whether you can trust a particular intuitive judgment, there are two questions you should ask: Is the environment in which the judgment is made sufficiently regular to enable predictions from the available evidence? The answer is yes for diagnosticians, no for stock pickers. Do the professionals have an adequate opportunity to learn the cues and the regularities? The answer here depends on the professionals' experience and on the quality and speed with which they discover their mistakes.

The most effortful forms of slow thinking are those that require you to think fast.