Discipline and control are necessary elements to develop within yourself as you study self-defense and fighting techniques. I can tell you from my own experience that training extensively in self-defense and fighting techniques has skyrocketed my levels of aggression, anger, and eagerness to fight. My roommate in college told me that he had a similar experience when he practiced kung-fu extensively. You MUST learn to control yourself and never go looking for a fight. Never go looking for trouble – you will find it. Someone cuts you off in traffic? Let them go, don’t honk your horn and flip your middle finger at them, or scream at them. Someone insults you or your significant other? Smile and walk away. Don’t get into a confrontation with them. If you contribute to the start of a physical altercation, in court you cannot claim self-defense to get out of legal trouble, you will almost certainly be convicted of either fighting or assault, which could land you in jail, or at the very least leave a permanent black mark on your record.
To help with discipline and self-control, I recommend regular meditation practice. In feudal Japan martial arts training normally included meditation practice. By learning deep breathing and mind-calming meditation, you will develop self-control and a calm mind, things which will help you in the midst of a heated confrontation or in an actual fight. By keeping your wits about you rather than giving into anger, fear, or other negative emotions, you will be able to avoid a fight, or if the fight is unavoidable you will be able to fight smarter, increasing your chances of emerging victorious or being able to escape to safety.
To start with meditation, first try the box breathing method. Find a quiet place to sit in a relaxed position where you won’t be disturbed. Breathe in for four seconds, hold it for four seconds, then breathe out for four seconds. As you do this try to keep your mind clear and calm. You may wish to imagine yourself in a calming environment as you do this. Mark Divine writes in his book Way of the SEAL about the “still waters run deep” method. As you practice the box breathing, imagine yourself at the bottom of a deep pond (also imagine that you can somehow magically breathe underwater). As a stray thought surfaces in your mind, let it go as a ripple on the surface of the pond. A variation of this that I like is to imagine myself at a dojo high in the mountains, with clear sunshine, a cool breeze, a pond in the foreground, and the sound of wind or birds chirping to represent the stray thoughts that come to mind and that I let go of.
Once you regularly practice deep breathing, in times of stress (whether work-related or an angry man getting in your face, looking for a fight) you can use box breathing to keep your stress levels under control and remain calm, cool, and collected. Learning how to fight is important, but learning to control your aggression and fighting skill is just as important.