Even without martial arts...knowing something, regardless of source, has to have the capability of destroying your 'enemy' because if we look at nations and colonialism, or with Germany in World War II as examples, those who not only appear weaker but carry no arms/weapons, often are the victims of those who dream of evil to do to their fellow man.
When Greyhound was the main transportation (San Diego and Arizona usually( (for me ) in the late 1970s, the people at the bus station who would be rolled tended to the the least capable of doing anything for themselves despite their less than desirable living circumstances. I would leave MCRD/Pendleton on weekends, go to the the San Diego Greyhound Bus Station and the victims usually had no means of defense of any kind and they lived on the street so nobody cared. Though I am not a gun carrier, we all know that those who show weakness become the targets, or at least the appearance of weakness so better to have a capability and by following some level of the usual situational awareness because the enemy will usually tell you what he is going to do so we must pay attention.