We live in a world in which people are censured, demoted, imprisoned, beheaded, simply because they have opened their mouths, flapped their lips, and… - Daniel Gilbert

There are many different techniques for collecting, interpreting, and analyzing facts, and different techniques often lead to different conclusions, which is why scientists disagree about the dangers of global warming, the benefits of supply-side economics, and the wisdom of low-carbohydrate diets. Good scientists deal with this complication by choosing the techniques they consider most appropriate and then accepting the conclusions that these techniques produce, regardless of what those conclusions might be. But bad scientists take advantage of this complication by choosing techniques that are especially likely to produce the conclusions they favour, thus allowing them to reach favoured conclusions by way of supportive facts. Decades of research suggests that when it comes to collecting and analyzing facts about ourselves and our experiences, most of us have the equivalent of an advanced degree in Really Bad Science.

The benefit of knowledge is that it makes the world more predictable, but the cost is that a predictable world sometimes seems less delicious, less exciting, less poignant.

My friends tell me that I have a tendency to point out problems without offering solutions, but they never tell me what I should do about it. In one chapter after another, I've described the ways in which imagination fails to provide us with accurate previews of our emotional futures. I’ve claimed that when we imagine our futures we tend to fill in, leave out, and take little account of how differently we will think about the future once we actually get there. I’ve claimed that neither personal experience nor cultural wisdom compensates for imagination’s shortcomings. I’ve so thoroughly marinated you in the foibles, biases, errors, and mistakes of the human mind that you may wonder how anyone ever manages to make toast without buttering their kneecaps. If so, you will be heartened to learn that there is a simple method by which anyone can make strikingly accurate predictions about how they will feel in the future. But you may be disheartened to learn that, by and large, no one wants to use it.