A former colleague actually still believed (almost certainly still does) that Diana was alive and it was all staged based on a newspaper headline "I'm going to change the world" she had read on holiday sometime before the accident. She dropped this bombshell into the conversation whilst giving a lift to a group of half a dozen of us in her people carrier.
I kept shtum (not much you can say to someone to convince them otherwise, when it then about 22 years after she had died), but another colleague made the point that the Princes seemed unlike their were faking their grief.
I think some people just live boring lives and eccentric ideas from their own "unique perspective" but based on no factual reality are their unconscious way of spicing up their mundane existence.