Which C.S. Lewis autobiography describes his return to Christianity?

Surprised by Joy is the C.S. Lewis autobiography describing his return to Christianity. Published in 1955, it covers his childhood, education, intellectual development, conversion, and changing understanding of joy.

Lewis uses “joy” in a specialized sense for an intense longing or fleeting desire that points beyond ordinary satisfaction. He connects this experience with books, Norse mythology, imaginative literature, and moments from his early life rather than presenting joy simply as happiness.

The autobiography recounts Lewis’s movement from atheism toward belief in God and then Christianity. His conversion was influenced by conversations with fellow Oxford writers, including J.R.R. Tolkien and Hugo Dyson, but the book is a personal memoir rather than a complete chronological history of every event.