In the late 1970s, a team of psychologists led by Philip Brickman came to a startling conclusion about humans and happiness. In comparing the happiness levels of a group of lottery winners and a group of paraplegics to that of the general population, the psychologists discovered that both life-altering events made negligible differences on the groups' well-being after a while. The researchers attributed this phenomenon to the adaptive functioning of the human spirit. Given time, people will acclimate to circumstances, whether fantastically positive or negative.
In the case of the lottery winners, a sudden jolt of wealth didn't improve their happiness in the long run. Instead, people can get trapped on what Brickman coined a hedonic treadmill, or an endless search for bigger and better material goods to bring pleasure. The problem with this pathological pleasure-seeking is its intrinsic emptiness. By definition, pleasure is momentary and fleeting -- leaving us wanting more. Contentment, on the other hand, means appreciating present circumstances and surroundings.