And, to a degree, he is right. In this world/universe, we are mere illusions that, with our limited human perception and lack of language to describe the fact that you and I and everyone around us are illusions that are of no real importance to us in Reality. I won't claim that the physical world doesn't exist because, as far as I know, it does. It's a plane of existence in which WE (our true selves) can be born into and experience a life as a human. Humans, however, are mere shadows (I know, that's what the cave analogy argues), shadows of our real selves. Illusions. You are Tim Anderson, Ph.D, an accomplished human being. In Reality, however, you are TIM ANDERSON, still yourself but with a far greater sense of Self, of being Tim Anderson than can be imagined from this plane of existence. As for Plato believing that we don't live in the real world, he is both correct and incorrect. As humans live in this world. Our true selves, our Selves, don't.