Why do I constantly have dreams of me shouting and getting angry?

About once or twice a week, I would have dreams of me saying, "No! Get out!" constantly and arguing with someone (mostly my brother). It usually happens around 5 or 6 in the morning and my Dad would wake up and hear me shouting. I can't really quite remember the dreams, but from what he tells me, it sounds like me telling my brother to get out (he's always in my room bothering me). I think he's concerned about these dreams because the way he tells me, it sounds like I have anger issues with my brother (he's constantly in my room messing it up and taking my things and farting).