The phrase you're not that guy spread online as a short hand way to call out inflated ego, turning into a reusable reaction clip across memes and short videos. Its appeal is the contrast between someone acting like the main character and a single flat line that shuts it down. Because the wording is simple and instantly understood, creators reuse it over gaming moments, gym clips, sports bravado and everyday fails, letting the sound do the roasting without needing extra context or explanation from the editor.