The Feet Keep Moving, and So Does the Mind

[Dickens'] favorite mode of exercise was walking; and when in America, scarcely a day passed, no matter what the weather, that he did not accomplish his eight or ten miles. It was on these expeditions that he liked to recount to the companion of his rambles stories and incidents of his early life; and when he was in the mood, his fun and humor knew no bounds. He would then frequently discuss the numerous characters in his delightful books, and would act out, on the road, dramatic situations, where Nickleby or Copperfield or Swiveller would play distinguished parts. I remember he said, on one of these occasions, that during the composition of his first stories he could never entirely dismiss the characters about whom he happened to be writing; that while The Old Curiosity Shop was in process of composition Little Nell followed him about everywhere; that while he was writing Oliver Twist Fagin the Jew would never let him rest, even in his most retired moments; that at midnight and in the morning, on the sea and on the land, Tiny Tim and Little Bob Cratchit were ever tugging at his coatsleeve, as if impatient for him to get back to his desk and continue the story of their lives. . . .