It’s funny with fiction - once you cut something, it hasn’t happened anymore.

Saunders is pointing to a distinctive feature of fiction as an art of selection: the story’s “reality” is not an independent record but something created by what the writer chooses to include. When a scene, detail, or subplot is cut in revision, it doesn’t merely become hidden background—it effectively ceases to exist in the world the reader will inhabit. The remark underscores why revision can feel metaphysically consequential: trimming isn’t just shortening, it reshapes causality, character, and meaning. It also hints at fiction’s ethical/aesthetic discipline—only what serves the story’s felt truth should remain, because the final text is the only reality the work can claim.