Isn't it amazing how some days we wake up and the world seems beautiful—full of wonder, kindness, heroism, and brilliance? No matter what the true weather is, the sun shines on us that day, the future seems promising and bright, we feel healthy and energetic, and our life is full of love. But other days, days on which our life hasn't really changed in any substantive way, we wake up to a sense of darkness, and a conviction that the world is miserly and ugly, that the people around us are malevolent and small-minded, that the mole on our shoulder is cancerous, that our past is wasted, and our future is bleak. How terrifically swayed we are by our in-the-moment emotions and ruminations. When we are fantasizing about relocating or are in the throes of an infatuation or bent on leaving our job or miserable about the fight we had last night, we can't imagine waking up tomorrow and feeling any differently. It's a bit like being so blinded by the sun (or so darkened by clouds) that we cannot see beyond the state of that singular moment.

The blinding power of our present state is highlighted by the difficulty we have in predicting how we would feel or behave in an alternate state. For example, a 2006 study by Dan Ariely and George Loewenstein showed that when we are sexually aroused, we err about what we might do and decide (e.g., about having sex with a stranger) when we are completely unaroused. Not surprisingly, the reverse is true as well. This phenomenon is called the "hot-cold empathy gap," because when we are in a "hot" state (like being aroused, in pain, thirsty, covetous, or curious), we have difficulty empathizing what our feelings and judgments might be in a "cold" state (like being completely unaroused, pain free, sated, or indifferent).