The phrase that's what she said has circulated for decades as a stock innuendo joke, but it became a mainstream catchphrase through The Office, where Michael Scott used it constantly to turn ordinary office dialogue into a suggestive gag. Clips of the line spread through television reruns, YouTube compilations and soundboards, and it later became a staple reaction sound in short-form video. It endures because the joke needs no context beyond the line before it, making it endlessly reusable in everyday conversation and comedy edits.