Which C.S. Lewis memoir describes his journey from atheism to Christianity?

C.S. Lewis’s memoir describing his journey from atheism to Christianity is Surprised by Joy. Published in 1955, the book recounts his childhood, education, intellectual development, and changing religious beliefs up to his conversion to Christianity.

The title refers to Lewis’s idea of “joy,” a powerful form of longing or desire that he associated with experiences of beauty and imagination. He describes how this longing influenced his reading and thinking, although the memoir is not a conventional day-by-day autobiography.

Lewis became a theist in 1930 and a Christian in 1931. His conversations with fellow Oxford writers, including J.R.R. Tolkien and Hugo Dyson, contributed to the intellectual setting of his return to Christianity. Readers sometimes confuse Surprised by Joy with The Pilgrim’s Regress, Lewis’s 1933 allegorical novel, or with A Grief Observed, his later book about bereavement.