Shota Aizawa, also known as Eraser Head, is the homeroom teacher of Class 1-A in My Hero Academia, the manga and anime series by Kohei Horikoshi, and he is famous among fans for his sleep-deprived, no-nonsense attitude. That reputation is why a short line calling him exhausting, or addressed to him, travels so well as a reaction sound: it borrows a familiar character trait rather than depending on one scene. Anime editors and meme makers keep reusing it for tired, fed-up moments because the joke is instantly recognisable even to viewers who only know Aizawa from clips and edits.