"The rational system thinks that happiness would be losing 15 pounds and looking good in a swimsuit. But the emotional system thinks that happiness would be plowing through an entire bag of Nacho-Cheese Doritos. For most people, the emotional system tends to win these debates because it’s incredibly powerful. The psychologist Jon Haidt has a great analogy: He says that the emotional system is like an elephant, and on its back is a human-scale rider that represents the rational system. The rider thinks he’s the one in charge, but c’mon. If the two ever disagree, who’s your money on? So if you want your rational system to win out, you’ve got to avoid a direct tug-of-war with the elephant. Don’t bet on willpower. If you’re on a diet, don’t assume that your self-control will keep you from raiding the ice cream. That’s foolish. Just throw out the ice cream."
-Dan Heath (co-author of 'Made to Stick')