The Lost Generation was the generation that came of age during World War I. Demographers William Strauss and Neil Howe outlined their Strauss-Howe generational theory using 1883–1900 as birth years for this generation. The term was coined by Gertrude Stein and popularized by Ernest Hemingway, who used it as one of two contrasting epigraphs for his novel The Sun Also Rises. Hemingway credits the phrase to Gertrude Stein, who was then his mentor and patron.
In A Moveable Feast, published after Hemingway's and Stein's deaths, Hemingway claims that Stein heard the phrase from a garage owner who serviced Stein's car. When a young mechanic failed to repair the car quickly enough, the garage owner shouted at the boy, "You are all a "génération perdue.":29 Stein, in telling Hemingway the story, added, "That is what you are. That's what you all are ... all of you young people who served in the war. You are a lost generation."
Lost in this respect means disoriented, wandering, directionless—a recognition that there was great confusion and aimlessness among the war's survivors in the early post-war years."
The 1926 publication of Ernest Hemingway's The Sun Also Rises popularized the term as Hemingway used it as an epigraph. The novel serves to epitomize the post-war expatriate generation. However, Hemingway later wrote to his editor Max Perkins that the "point of the book" was not so much about a generation being lost, but that "the earth abideth forever"; he believed the characters in The Sun Also Rises may have been "battered" but were not lost.
In his memoir A Moveable Feast, published after his death, he writes "I tried to balance Miss Stein's quotation from the garage owner with one from Ecclesiastes." A few lines later, recalling the risks and losses of the war, he adds: "I thought of Miss Stein and Sherwood Anderson and egotism and mental laziness versus discipline and I thought 'who is calling who a lost generation?'"
The writings of the Lost Generation literary figures tended to have common themes. These themes mostly pertained to the writers' experiences in World War I and the years following it. It is said that the work of these writers was autobiographical based on their use of mythologized versions of their lives. One of the themes that commonly appears in the authors' works is decadence and the frivolous lifestyle of the wealthy. Both Hemingway and Fitzgerald touch on this theme throughout the novels The Sun Also Rises and The Great Gatsby. Another theme that is common for these authors was the death of the American Dream, which is exhibited throughout many of their novels. It is most prominent in The Great Gatsby, in which the character Nick Carraway comes to realize the corruption that surrounds him.