Christianity Today Magazine: "In early April, he wrote to a friend who had reproached him for not replying promptly to a letter, 'Dog's stools and human vomit have made my day today: one of those days when you feel at 11 a.m. that it really must be 3 p.m.' Two months later, he collapsed at his home and had to be taken to the hospital. He was diagnosed with strep throat, but his deeper complaint was simply exhaustion.
Such was C. S. Lewis's world the evening he had Roger Lancelyn Green to dinner. It's unlikely that Green had any idea how miserable his friend had been. Lewis was a charming host, and, as Green wrote in his diary, they had 'wonderful talk until midnight: He read me two chapters of a book for children he is writing—very good, indeed, though a trifle self-conscious.' The book would become The Lion, the Witch and the Wardrobe, the first story about a world called Narnia"
Interesting backstory to Narnia.