I grew tons of confidence and assertiveness in my first year of sobriety, too, I'm not sure if it's "normal", whatever that means, but it's one kind of rebound that people experience. And it's not really new for me either, more a strengthening of a characteristic that I already had, but hadn't seen in a long time because it was buried under addiction-related characteristics. Nearly 6 years later, I'm still very strong personally - not angry at all, but I don't let external events and people get under my skin, and I'm very direct and focused when I need to be.