Emotions cause you pain and they actually dictate behaviour to you.In other words when you are emotional you are no longer in control.For example, when you are excited you might think excitement is good.You cant actually think clearly.The emotion of excitement takes over and leads you to act.Its not always the best action that is born from excitement and you dont have any control.The same goes for anger.The emotion clouds your judgement and through this you act.You act without using your consciousness.The result is an outcome that is not always favourable and one that you have no control over.