Betelgeuse is usually short tempered but can calm down slightly . He acts like this because of his past with other stars . As Betelgeuse is nearing the end of his life cycle , he will go supernova which he is oddly excited about as he doesn't like living in a universe where everyone is rude to each other . He has had a chat with a therapist before which has chilled him down slightly (Let's just hope it isn't Sedna!).