According to a study by economists, the U-curve is generally noticed at age 46. It tends to appear in wealthier countries.

However, some economists and psychologists factor in the possibility that those who become happier in the studies are the same people who are content in their early years.

When we are young, we are often over-optimistic about the satisfaction we will gain out of our future successes. With age, as our ambition drives us to more, we don't feel the satisfaction we expected, so we wonder if there's something wrong with us.

It is only once we realize that our values change with age - in that we savor other simpler pursuits such as relationships, a hobby, or volunteer work - that we gain satisfaction.

There is a huge amount of untapped wisdom and potential in older people.

Because of the happiness curve, they are often in a position where they desire to give back by being mentors, volunteers, or work easier jobs, which allow them to use their skills.