Mainstream American culture has a real thing for happiness. We believe happiness to be the most important goal of human life. We also believe that people (at least those who are strong, self-reliant, hard-working, and virtuous enough) can achieve happiness if they pursue it. Neither belief is completely true, but most of us are motivated to remain convinced of both of them.
Fortunately, these beliefs have powerful social benefits: they lead to a broad acceptance of differences in human lifestyles and behavior. Common expressions like "different strokes for different folks" or "whatever floats your boat" acknowledge that different people seek different paths to happiness and that we won't always understand the choices that others make along the way. However, we can accept and even applaud any number of unusual behaviors if we can see them as ways of pursuing and achieving happiness. For example, if I leave a high-ranking position in a big corporation for a life raising chickens on a small farm, my friends will ignore their initial misgivings if they believe this life change could make me happy.