Being happy is about feeling good. Meaning is derived from contributing to others or to society in a bigger way.
The unstated premise of our society is that all of us are born at some level on a socio-economic ladder. Our prime directive is that we must dedicate a substantial part of our waking hours and efforts to climb to higher and higher steps on that ladder. At any step on the ladder we can look down to the comparatively diminished lives we had on the lower steps. And at the very top we–or our descendants–will have attained that perfect Nirvana, the frictionless existence that comes in tandem with virtually limitless wealth.