Your mistake was not in imagining things you could not know—that is, after all, what imagination is for. Rather, your mistake was in unthinkingly treating what you imagined as though it were an accurate representation of the facts.

The word happiness is used to indicate at least three related things, which we might roughly call emotional happiness, moral happiness, and judgmental happiness.

Variety improves the things that we do too often, but it rules the things that we don't do often enough.

Impact is rewarding. Mattering makes us happy.

Your mistake was not in imagining things you could not know—that is, after all, what imagination is for. Rather, your mistake was in unthinkingly treating what you imagined as though it were an accurate representation of the facts.

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.

The brain and the eye may have a contractual relationship in which the brain has agreed to believe what the eye sees, but in return the eye has agreed to look for what the brain wants.