If I agree with the above, I can set aside the quest for ultimate measurement of absolute happiness (e.g. Solon's "Count no man happy until he be dead.") . However, I can still do things that affect relative happiness. When I stopped consulting for boring ERP software, my quality-of-life definitely improved. Again, I won't know if I'm ultimately "happy" until I'm lying on my deathbed. Nevertheless, it feels like I got a little victory from changes like that.