Wow. You suggest there are people who are both perfectly happy AND healthy out there.
A more relevant question is: What evidence do you have that such people are, as you say, "perfectly happy and healthy" , and, how do you distinguish them from those who are not ? I would be curious to know the criteria upon which you adjudge someone to be perfectly happy AND healthy.
Absent a criteria of evaluation, I do not believe your position is tenable.