Your mind is the greatest weapon. Hope and pray the arts of war never have to be used, but be prepared to do so with conviction and commitment, without hesitation. It is not pleasant, but must be thought through before you have to take action, not waiver on if you are going to make a decision to act.
Knowing and possessing the means of warfare means little without having the mental tenacity and acceptance that what we study, are methods of combat, a wrath of incapacitating and lethal techniques. One must stand back and understand, and accept, that it is in fact, what we do, what we study, and be prepared to unleash and apply whatever level of force required in unpleasant circumstances. I think the "sport" aspect of many strip mall clubs desensitize the lethal nature of martial art and most people do not consider the outcomes of applying what they learn, let alone the unpleasant (at best) circumstances in which they would have to be deployed.