My mom gets mad for the stupidest reasons ever!?

We were watching this kdrama on the comp, and my bro comes over and she tells him to get her a gl of water. she always does this... and then my bro is like "No! Make do it!" ofc, my name is not . just a nickname. lol... BUT YOU KNOW WHAT? I ALWAYS GOT HER A GL OF WATER, I DID EVERYTHING, I EVEN CUT UP THIS ONE VEGETABLE THAT STUNG MY EYE LIKE HELL. and what did he do? lock the door of his room, sleep, eat, and hog the computers and get aggressive. and then my mom got mad and my bro went upstairs to keep watching vids on the ipod and she was yelling at me and threatening me. WHO GETS MAD OVER THOSE REASONS?