A childhood belief about i'm different

I spent many hours convincing myself that the world was play acted for my benefit; that people would be milling around in whatever room I was about to walk into, and then spring into appropriate action when I would enter.
As an adult, when the movie "The Truman Show" was released with almost this exact plot (in my mind there was no show, it was just reality, and all the people weren't really actors, but more like automatons), I started reading reviews talking about 'this common childhood fantasy we all had of being the only real person in the world'.
So I went from great surprise that someone had written a movie about my childhood obsession, to shock that loads of people thought the exact same thing.