Yea, I'm not going to live like that. My pistol is not going to keep me safe from some person with body armor and a rifle intent harming as many people as possible. Even if I had my gun on me, which I would not because I just don't want to carry, I think getting as far away from the threat is the strategy. There is no way I could switch gears mentally from being out shopping to dealing with some sort of threat. It's one thing to be in a tough spot at work, when you're mentally prepared for that. I am not going to be mentally prepared for much when I'm at a bar with my friends. I know this about myself. I keep seeing this whole "if only there was a good guy there with a gun" mantra and I just don't get it. I hope your (I mean this in the plural sense) training will allow you to find cover, avoid shooting one of the dozens of panicking people nearby, and keep you from getting shot yourself, either by the perpetrator or law enforcement. If it does great, but I think we should all remember that this sort of training is a huge commitment and proficiency is challenging even for law enforcement, who at least have the benefit of going to work everyday with a prepared mindset.
I also respect that there are many reasons to carry a gun. I do not intend to dissuade anyone from doing so. I am not some bleeding heart that hates guns. I just hope pragmatism will prevail.