It can be inferred that you lack confidence in a victory over your rivals from the fact that you’re irritable against them. From that you would get angry with your friends, we can conclude you sitll care about the friendship between you. (如果敌人让你生气,那说明你还没有胜他的把握;如果朋友让你生气,那说明你仍然在意他的友情。)