What is the author's tone in Surprised by Joy by C. S. Lewis?

Lewis tells his story without sentimentality or the slightest note of hubris, but humbly and even, at moments, as a humble confession. He lays himself as bare as an honest and complete telling of his story requires, careful to disclose even the faults in himself that led him to mistaken thinking, not shying away from a single topic. He even anticipates the questions in his readers' minds and answers them on the spot, interrupting the telling of his story to complete the understanding of the reader before moving on.