Developing pieces of accents?

I just find it kinda funny is all... I'm from Texas, but I have a mild American accent for the most part- but when I'm angry or raise my voice to liven up a conversation, Boom! It's either Canada, Ireland, or Montana. I watch a lot of movies and speak in accents to quote things for friends, but my family teases me when I unintentionally do it. Does that happen to other people? :)