What are the motifs in Surprised by Joy by C. S. Lewis?

Joy as a path to God is a recurring idea in the book. The majority of Lewis' life was peppered with experiences of joy that he was constantly trying to recapture and grasp for longer than the flashes of an instant for which they lasted. Each of the literary pleasures he discovered, the new perspectives on nature, the moments of felicity at the discovery of another pleasure of any kind led him to wonder whether this might be the thing that would allow him to hold on to that bliss forever. Particularly when he was reborn into his acquaintance with joy following the dark ages of his boyhood, he looked for joy in all manner of counterfeiting experiences.