“I once said to a friend that I suspected the happiness of stupidity was greatly overrated. And she shook her head seriously, and said, “No, it’s not; it’s really not.” Maybe there are stupid happy people out there. Maybe they are happier than you are. And life isn’t fair, and you won’t become happier by being jealous of what you can’t have. I suspect the vast majority of Overcoming Bias readers could not achieve the “happiness of stupidity” if they tried. That way is closed to you. You can never achieve that degree of ignorance, you cannot forget what you know, you cannot unsee what you see.” (Eliezer Yudkowsky, Rationality)

Happiness of stupidity is a tough phrase. While there is a point to it, it is arrogant.