TED: Dan Gilbert: Why are we happy? Why aren't we happy?

Apropos of Nate's post on "Status and Curiosity - On the Origins of Oil Addiction" earlier this week, and Stuart's post "Happiness, economic growth, and oil prices", here's Dan Gilbert, author of Stumbling on Happiness, who challenges the idea that we’ll be miserable if we don’t get what we want. Our "psychological immune system" lets us feel truly happy even when things don’t go as planned.