This story gives some insight into Dad’s sense of humor, which helps explain where Ishmael developed the sarcastic tone that he uses throughout the novel. But Dad does seem to be making these jokes in attempts to get his wife to feel better, showing that language can, in some cases (though perhaps not in this one), help improve people’s outlook. Dressing up as Captain Ahab is a nod to Herman Melville’s whaling novel
Moby-Dick, and it introduces the novel as a symbol for Ishmael’s relationship to his name.