Hemingway maintains, throughout his career, that to even talk about writing, to come even close to revealing any of the secret behind what he calls inventing ?one true sentence,? inevitably leads to the removal of some great luster, some mysterious and vital force hidden beneath the words. Yet Hemingway demonstrates a knack for completely and almost casually disregarding his own advice, going to great lengths in order to divulge and describe his own writing process, especially his so-called ?new theory? of omission. As he explains in A Moveable Feast, ?you [can] omit anything if you [know] that you omitted and the omitted part [will] strengthen the story and make people feel something more than they [understand].? Hemingway consistently seems to contradict himself, however, both refusing to discuss anything about writing or the theory of omission and then, almost immediately, launching into a detailed account of the process, revealing all the details left out of his work. In this paper, I argue that Hemingway appears compelled by a certain amount of nostalgia to fill in the missing pieces, to revisit the past and expose the things omitted and left behind, reincorporating all the lost and absent fragments. Focusing on a specific biographical instance of omission, the traumatic loss of Hemingway?s early manuscripts in 1922, and examining the way in which this event reappears compulsively in his later writing, my presentation seeks to demonstrate the limitations of the omission theory, illustrating Hemingway?s need to reclaim the ?things left out.?