Daniel Kahneman

People are very complex. And for a psychologist, you get fascinated by the complexity of human beings, and that is what I have lived with, you know, in my career all of my life, is the complexity of human beings.

You know, the standard state for people is 'mildly pleasant.' Negative emotions are quite rare, and extremely positive emotions are rare. But people are mildly pleased most of the time, they're mildly tired a lot of the time, and they wish they were somewhere else a substantial part of the time - but mostly they're mildly pleased.

If a man made himself an expert in any particular branch of human activity, there would result the strong tendency that a peculiar aptitude towards the same branch would be found among some of his descendants.