Which C.S. Lewis book is a memoir about his return to Christianity?

C.S. Lewis’s memoir about his return to Christianity is Surprised by Joy.

Published in 1955, Surprised by Joy recounts Lewis’s intellectual and spiritual development from childhood through his conversion. It describes his early fascination with mythology, his education, his service in the First World War, and the friendships and arguments that influenced his changing beliefs.

The title refers to Lewis’s idea of joy as a brief, intense longing triggered by experiences such as literature, nature, or imagination. He treated this longing as important evidence about the direction of his spiritual search, although he distinguished it from ordinary happiness or pleasure.

The memoir ends with Lewis’s return to Christianity rather than narrating his entire later public career. Readers sometimes confuse it with A Grief Observed, which is a record of mourning after Joy Davidman’s death. Surprised by Joy is primarily an intellectual and spiritual autobiography.