"What lies behind us and what lies before us are tiny matters compared to what lies within us"
- Ralph Waldo Emerson
Many times in life, whether we like it or not, perception is reality and budo is no different. As a warrior, we must be forever diligent and thus must be en garde at all times. We can expect to be attacked anytime we let our guard down. Therefore we cannot leave any openings.
There is a famous Japanese saying, bushi wa kuwanedo taka yoji (武士は食わねど高楊枝) which means a "A samurai, even when he has not eaten, uses a toothpick like a lord."
Most think it means that a hungry samurai chooses pride before poverty. Another way to understand it is that if one lets on that they haven't eaten and are hungry then they will be weak and thus an easier target for attack. The perception of weakness can then lead to a person being attacked.
In training, we constantly trying to ensure that our intentions match our reality. If we want people to think that we are respectful then we must act respectfully. If we want people to think that we are humble, we should then act with humility. Conversely, if we want people to think we are jerks then we should act like a jerk.
Like it or not, people "judge" us by the things that we say and do. Our job as martial artist is to make our actions and our words line up with our intentions.