That's probably not true. There's the Dalai Lama and Simeon II of Bulgaria, who were minors but at least Simeon surely remembers (his father died in suspicious circumstances, he had an unconstitutional regency, and then he was dethroned, expelled and spent his life in exile).
> Now that generation that remembered the horrors of fascism has mostly passed and we find ourselves in a period that seems to have many echos of the 1930s with a new rise of authoritarianism and fascism around the world
It's honestly infuriating that with the wealth of information available at everyone's fingertips so many people are so easily making the same mistakes as a century earlier.
Monarchy is not necessary hereditary. And replacing monarch with sovereign, doesn't change the fact that it's a monarchy.
I guess the only real definition of monarch is social and cultural: someone who claims to be one and is broadly recognized as such.