My impression of our late queen was that she wasn't an intellectual.
She was a more practical person who loved animals and the outdoors.
But she did her duty, to know what she needed to know, no doubt with huge support.
I'm sure if he had the temperament for duty H could have done the same with the same level of support and his lack of intellect wouldn't have been exposed.
But he thought he's personally something special rather than him being an average person fulfilling a special role and he's exposed himself as an idiot.
The Queen was exceptional in her commitment to duty.
I don't think she believed she was exceptional in other ways.
Maybe her talent with horses?
She obviously also had flaws.
Because she was a person, doing a role.