When it becomes clear to Mr. Bixby that Twain is not "learning the river," he gives his cub pilot some good advice:

My boy, you must get a little memorandum book, and every time I tell you a thing, put it down right away. There's only one way to be a pilot and that is to get this entire river by heart. You have to know it just like ABC . . . .

Twain takes Bixby's advice and soon his notebook "fairly bristled" with information. Twain says he recorded in his notebook "the names of towns, "points," bars, islands, bends, reaches, etc." It bothers him tremendously that his book is incomplete since he misses much of the river every time he sleeps.