The line comes from Invader Zim, the Nickelodeon animated series created by Jhonen Vasquez that follows the alien Zim and his human classmate Dib, who is determined to expose him. Dib's age became a memorable part of his character, and short clips of his voice have circulated on meme soundboards and in fan edits for years. Creators keep returning to it because it instantly identifies Dib and adds a self-aware, childlike excuse to jokes about growing up, responsibility, or being underestimated.