Daniel Gilbert is a psychology professor at Harvard, and is most famous for his international best-selling book, Stumbling on Happiness. Gilbert often tells people that he has spent a great deal of his academic life studying happiness.

Much of Gilbert’s research on happiness has been in collaboration with psychologist Tim Wilson from the University of Virginia, economist George Loewenstein of Carnegie Mellon and psychologist (and Nobel laureate in economics) Daniel Kahneman of Princeton. These four men have done some exceptional work as they have questioned the decision-making process that shapes our level of happiness. They have discovered that we do not know how to predict what will make us happy or unhappy.

For instance, how will we feel if our favorite college football team wins the game on Saturday? How will we feel a few days after the game? How do we predict we will feel buying new jewelry, a new set of golf clubs, or a new home? Our decisions are based on our predictions of the emotional consequences of these events.

What these men discovered is that we do poorly when it comes to imagining how we will feel about something in the future. We have this propensity to overestimate the intensity and duration of our emotional reactions to future events. They learned that material possessions or pleasurable experiences will not be as exciting as they had anticipated, nor will it be as exciting for as long as they predicted.

Growing up, I did not have my own automobile until I graduated from college. My first purchase was a small red Toyota Corona. It was not the vehicle I wanted, but I was grateful to have transportation. Five years later, the Toyota was paid for, I was making more money, and I set my eyes on a more expensive vehicle that I believed would transform my life and lead to greater happiness. I was convinced of it.

The vehicle I wanted was a new Oldsmobile Cutlass Supreme. It was a beautiful dark gray with a lighter colored top. I remember driving it off the dealer’s lot on Saturday morning and I was fit to be tied. The next day as I drove into the parking lot of the church I attended, I anticipated positive comments from my friends, which I did receive. I could not wait until Monday morning rolled around when I would park in our company parking lot. As I expected most of our company’s employees spilled out into the parking lot to examine my new car. I was elated and truly believed life could not get any better than this.

It was about ten days later that it dawned on me that the thrill was gone. I realized then that my love and appreciation for this new car was no different than the Toyota I had traded in. It was a great life lesson. I have realized not to look at vehicles or any material possession as a source of personal happiness. It just can’t deliver.

Gilbert and his colleagues who have studied this issue over the years call the gap between what we predict and what we ultimately experience as the “impact bias.” They use the word impact to describe the errors we make in estimating both the intensity and durations of our emotions. The word bias is used to describe our tendency to err. This phrase characterizes how we experience the diminishing excitement over any object or event that we presume will make us happy. We may predict it will lead to our happiness, but it will almost always not turn out that way.

Richard E Simmons III is the founder and Executive Director of The Center for Executive Leadership and a best-selling author.