Kurt Vonnegut's early ventures in journalism and advertising largely influenced his writing style. Initially, he worked in public relations and produced short stories reflecting his observations of society. His experiences during World War II, particularly his capture in the Battle of the Bulge, deeply affected his narratives, leading to themes of suffering, absurdity, and the human condition. This blend of satire and humanism became hallmarks of his later works, especially in novels like "Slaughterhouse-Five," where his experiences inform both the plot and its existential themes.