Would a 20 percent raise or winning the lottery result in a contented life? You may predict it will, but almost surely it won't turn out that way. And a new plasma television? You may have high hopes, but the impact bias suggests that it will almost certainly be less cool, and in a shorter time, than you imagine. Worse, Gilbert has noted that these mistakes of expectation can lead directly to mistakes in choosing what we think will give us pleasure. He calls this "miswanting."

"The average person says, 'I know I'll be happier with a Porsche than a Chevy,' " Gilbert explains. " 'Or with Linda rather than Rosalyn. Or as a doctor rather than as a plumber.' That seems very clear to people. The problem is, I can't get into medical school or afford the Porsche. So for the average person, the obstacle between them and happiness is actually getting the futures that they desire. But what our research shows — not just ours, but Loewenstein's and Kahneman's — is that the real problem is figuring out which of those futures is going to have the high payoff and is really going to make you happy.

An interview of the wealthiest as determined by Forbes magazine found they are only slightly happier than the "average" person. Experts say the problem is "miswanting."

What people think they want many times is not really what they want at all. Study participants were asked to choose what they would like to eat on three consecutive Mondays. When it came time to eat the snacks, most were unhappy with their choices. They said what sounded good at the time wasn't what they wanted when it was time to eat them.