Surprised by Joy is C.S. Lewis’s autobiographical account of his conversion, published in 1955.
The book traces Lewis’s intellectual and spiritual development from childhood through his return to Christianity. It discusses his early loss of religious belief, his interests in mythology and literature, and the experiences of longing that he called “joy.”
Lewis’s conversion was gradual rather than the result of one isolated event. He returned to belief in God during the late 1920s and became a Christian in 1931. His conversations with J.R.R. Tolkien and Hugo Dyson were important to that later movement toward Christianity, especially concerning myth and the Christian story.
Surprised by Joy is not a complete diary or a detailed day-by-day record. It is a reflective memoir, and Lewis acknowledged that memory and interpretation shape the narrative.