According to Writer’s Almanac, one day, while grading exams, J.R.R. Tolkien discovered that a student had left one whole page in his examination booklet blank. Tolkien, for reasons unknown even to him, wrote on the page, “In a hole in the ground there lived a hobbit.” This single line turned into a bedtime story that he told his children, and from there, a book: The Hobbit (1937).