Soceity (and somewhat we...) want us to perform well. To be efficacious, our emotions to be in order etc.
this is very different from the good life, and sometimes even opposes it.
The good life is about feeling good, about enjoying what we are doing, not about being an efficient soldier in the world.
Functioning well has clearly many advantages, and at times functioning well makes a happy experience. The mistake is when one mistakes functioning well to happiness. (or seeing hard work (Puritanism) or well functioning (normalcy etc.) as a goal in life or a reason to stay alive.)
I noticed the functioning happiness seperation clearly when seeing unhappy countries. you still see the full range of human experience in what feels like entirely healthy functioning. Yet the unhappiness is evident and saddening to look at.