Compared to Cao Cao, who was only shocked upon hearing the news of Yuan Shao's death and immediately started thinking about how to deal with Liu Bei, Yuan Shu was utterly dazed when he received the same news.
Yuan Shu had always strongly disliked Yuan Shao, primarily because Yuan Shao always seemed to be just a bit better than him. As children, Yuan Shu couldn't beat Yuan Shao in fights. He disdained resorting to insults, but every time he tried to confront Yuan Shao, he ended up with a bruised and swollen face. Although their father always stood behind Yuan Shu, he felt that such grudges ought to be settled by himself.
Unfortunately, Yuan Shu had never once succeeded in avenging himself directly. No matter how much Yuan Shao was scolded by others, as long as Yuan Shu dared to provoke him, Yuan Shao would never hold back. Even if their father would punish him later, Yuan Shao didn't care at all and would first give Yuan Shu a good beating.