“Nah, I'd win” spread online from Jujutsu Kaisen as a memorable line tied to Satoru Gojo, and it became a major meme in 2023. Even outside anime fandom, people started using it as shorthand for exaggerated confidence, usually when the outcome is obviously uncertain. The phrase took off in reaction images, short video edits and versus jokes because it is brief, recognizable and easy to place before a comedic loss. That mix of confidence and irony is why the sound still shows up so often.