I have most definitely not mastered my emotions. In fact, I have a hard time controlling them. It's probably why my kids turn into little tyrants when they get upset about something. It's something I am constantly working to improve and to teach them to better control their emotions.
I just read this article by Nicholeen at Teaching Self-Government. It's a great site and she has some really great insight.
How to Control Your Emotions
Take a go at it and let me know what you think!