Thing he has ever known was a lie. However once he saw matrix he could never go back to believing what he had known before. As for the Allegory of the cave the light is what hurt the prisoner 's eyes and made it difficult for him to see. What is meant by difficult to see is how the prisoner not wanting to believe where he had been living was not real. This compares to the matrix once he saw the light outside the cave the prisoner can 't believe in what is in the cave anymore.