Is there a formal a word or phrase that refers to or describes a blissful yet idiotic person? Preferably a one word way to say "stupidly happy", but I'm open to idioms as well.
For example, a word that describes the kind of person who would ask "Why don't homeless people just buy themselves a house?" Someone who is always carefree, and cannot comprehend the concept of stress or difficulty.
I specifically want to describe a fat and wealthy British gentleman from the 1800s. Google was not helpful, it only yielded slang and references to a movie from 2014.