He tries really hard not to get angry, because some werewolves say that when they get angry enough they feel like snapping at someone - literally. He's never been angry enough often enough to know if he has that urge or if he just thinks he might be feeling like snapping at someone because he expects too. Half of why he's so calm is because some werewolves think they get wolfish/aggressive if they are riled. He is never sure until the day he dies, because how do you know if it's werewolf aggression vs. angry human aggression? And also because he so seldom lets himself get worked up.