Alas, we think of ourselves as unique entities-minds unlike any others-and thus we often reject the lessons that the emotional experience of others has to teach us.

In short, we derive support for our preferred conclusions by listening to the words that we put in the mouths of people who have already been preselected for their willingness to say what we want to hear.

If I wanted to know what a certain future would feel like to me, I would find someone who is already living that future. If I wonder what it's like to become a lawyer or marry a busy executive or eat at a particular restaurant, my best bet is to find people who have actually done these things and see how happy they are.

Few of us can accurately gauge how we will feel tomorrow or next week. That's why when you go to the supermarket on an empty stomach, you'll buy too much, and if you shop after a big meal, you'll buy too little.

In short, if we adhere to the standard of perfection in all our endeavors, we are left with nothing but mathematics and the White Album.

The mistakes we make when we try to imagine our personal futures are also lawful, regular, and systematic. They, too, have a pattern that tells us about the powers and limits of foresight in much the same way that optical illusions tell us about the powers and limits of eyesight.

Impact is rewarding. Mattering makes us happy.