I also have never had a gun pointed at me. I have been in a training environment wherein every single person, hundreds of them including children age 12 and older, were armed, much of the time with fully loaded handguns. I felt perfectly comfortable.
However, I understand your concern about every armed person making the right choice in the use of deadly force, especially those afflicted with mental/emotional, prejudicial, and disability issues. And yes, there are those who spoil for a fight and those who accept the invitation to fight.
In the gun culture circles in which I associate, our mantra is, the best gun fight is the one that never happened. Conflict avoidance and escape, if at all possible, is best. Only in the case of there being no escape, and wherein an attack is clearly imminent, the attacker has the means, the attack would likely result in serious injury or death, AND there has been no incitement on the part of the victim(s) is the use of deadly force lawful by civilians.