A good number of people who didn't live on farms had to have the facts of life explained to them after their marriage, Mel!!! (My favorite honeymoon story, from my aunt, born 1902, was a friend who came back and said, "Well, it's sticky." Yes? "You take off your clothes and he throws biscuits and jelly at you." This was not a woman of royal blood.)
Back to the task at hand

I'm with Jane. I hate the term "Cardboard Prince." I think modern Siegfrieds spent so much time and effort trying to make a flesh and blood character out of Siegfried the wrong way -- adding a glower here and a wink there. A really great Siegfried just Is. Dowell was no piece of Cardboard. I didn't know a thing about him -- his past, his thoughts about his mother, his thoughts on comparative brands of crossbows, what he got on his last algebra paper. "But I love not," he mimed when his mother springs the betrothal ball on him. Not gay, not an air head, not a congenital idiot -- a Prince who awaits his destiny.
I once asked a Danish James why James was special -- Effy loves him, the Sylph loves him, even the witch loves him. "He is the hero," I was told. "You cannot ask why he is special." I thought of that for a long time before I understood it, but I think that's the key to the Princes. They're heroes. They don't have biographical details. They have destinies.