A fighter, a real strong fighter should always look dignified and calm and I believe that any expression of aggression is an expression of weakness. A strong person will not be nervous and will not express aggression towards his opponent. He will be confident in his abilities and his training, then he will face the fight calm and balanced.
We have the freedom to excel or inhibit our potential. You are the grand designer of your thoughts and emotions. At some level or another you are the one who chooses which thoughts to accept and which ones to ignore. That can be a very empower realization.