By your theory, for humans' dissatisfaction to cease, we must revert back to a time with little to no expectations. However, these expectations were wrought from the rules of society which were created to maintain the general welfare. Humans are relative to non-sapient animals, however we are not the same. We cannot live the wild life of a wolf, else we become discontent and our full brain capacity unused. Take for example, Lord of the Flies. Now obviously, the point of the book was more align with the Robbers Cave Experiment, but my focus is how the boys established a government (as result from social priming) and the disastrous results of its failure. When laws could not be properly enforced, they fell back to savage behavior driven mostly by the instinct to survive. (If you reread the book's summary and imagine it's a documentary of wolf pack interaction, the instinct driven actions are apparent.) Now the word "savage" is relative to our definition of being human, but I use it mostly to describe the general unhappiness of the boys. They were dissatisfied with a simple life of hunting/gathering and without proper laws, quickly fell into chaos. Humans are naturally incredibly more perceptive than any other animal, thus more laws are needed to govern the population. The more intelligent the animal, the more needed to maintain "peace" (see: a colony of bacteria vs a pack of wolves). People are discontent and pressured by society, but not because people weren't meant to live in a society of this kind. Humans are driven by their instinct of survival. Naturally, our minds link successful people as those with the highest fitness (the wealthy can buy good food and shelter, able to alter appearance to attract potential mates, the symbol of status able to attract potential mates, etc). Thus, many people falling short of this image of success and survival, are left unsatisfied.