The phrase comprate un cerebro is Spanish slang for buy yourself a brain, a blunt insult used when someone says or does something remarkably foolish. Online it circulates as a short reaction sound in Spanish-language memes, gaming clips and short-form videos, where creators use it to call out bad plays, failed logic and self-inflicted mistakes. Its appeal is its brevity and directness, a single cutting line that needs no explanation, which is why it keeps appearing in reaction edits and comment-style videos long after its first viral uses.