I use anger constantly to feel validated and smart. If I'm lonely or bored or hungry I need a hit. It's mostly mental, the way it pools up in my head and I start to think about issues or people who anger me, and with that anger pumping in my veins, I can accomplish almost anything I need to accomplish. I don't yell or scream, I don't hit or punch, I just think.
It's worth a read, especially if you ever feel your angsty teenage self come a creepin.