The Eternal, Charming Chatter of the 'Autobiography of Mark Twain: Volume 2' : The New Yorker: He often had trouble sleeping, and drank to numb his nerves. But he never had trouble talking.
He kept talking until the end. In the last years of his life, when he began writing his autobiography, Twain decided to do it mostly by dictation. He sat in bed, with his head propped up on pillows, and riffed and reminisced for hours at a time, while his stenographer took down everything in shorthand. When he was done, he had more than five thousand pages of typescript.
The result is the “Autobiography of Mark Twain,” a monster that has haunted Twain scholars for a hundred years.