If it is true that ignorance is bliss, I am surprised that there are not many more blissfully happy people in this world.
Ignorance, of course, has quite little to do at all with acquired knowledge or education and is more often a direct measure of a person (or group) being unable to accommodate the possibility and validity of a plausible infinity of other perspectives and valid insights that exist beyond the narrow island and close horizons of their own hollow belief systems.
Many people learn, like Pavlov’s dog, how to unthinkingly, reflexively juggle and shuffle the simplistic clockwork rules of systems of thought that are either dramatically anachronistic or are otherwise little more than self-validating excuses for their continuing existence as conceptual constructs.
I think sometimes that I would truly be happy if I was a complete idiot but then the irony is that you need to be relatively clever to realise that.
Intelligence provides the aptitude to consider a possibility that the world might be other than what it is.