The worm, the robot, and the cave of shadows

It is exactly the latter question that usually causes the whole grand edifice of digital immortality and consciousness upload to fail. The big idea that what we perceive is not real and that all is pure mind was articulated by Plato in the 5th century BC. He described humanity living in chains inside a cave, and able to seeing only shadows on the walls of the cave that we mistake for reality. Plato suggested that only by "awakening" could someone discover the truth, and break free of the illusionary cave. Plato's ideas have informed much of Christian theology.