Like the post above, thats' the way I see it. For the last few months he's been King, and calling everyone else his loyal subjects, etc. And now, with the World Title, wouldn't that only feed that ego? It would only make him believe even stronger, and he is King, he's top dog, and everyone else are just loyal subjects. Much like said above, a trophy, or a crown. I don't think it's stupid at all.
And I think it's pretty obvious his "King" Persona has gone far past just meaning 'king of the ring'.