C.S. Lewis's life was influenced by key experiences such as his formative years during World War I and personal losses. He lost his mother at a young age and later faced the horrors of war, which prompted deep reflections on faith, suffering, and existence. His time at Oxford University exposed him to diverse philosophical ideas, shaping his Christian beliefs. These elements greatly informed his writings, notably in "The Chronicles of Narnia" and "Mere Christianity," where he addresses themes of love, redemption, and morality.