I am reminded of some of my interactions with adults who play life that same way; when they are winning, or getting their way, they are happy and excited and want to keep playing, but if they are not getting their way, or aren't winning - watch out. It's one thing when it's a 9 year old child, and a completely other thing when it's an adult.
So what is the problem? Emotional insecurities. Adults who can't play by the rules, or follow a leader, or do what their Boss says (even when they don't agree) or listen to the advice of others is just acting like a child. Let's be honest here, we all struggle with this from time to time, but if it's a constant struggle for you, then you need to grow up. No one wants to play the game of life with a 30 year old child.