They are legally considered adults, however as statistics go, until they turn twenty they are considered part of the teen cohort. However, I did. Do you agree 13 year olds are tweens? Do you agree a nine year old should be safe from getting shot at school, church, temple or parade?
Here is more for you. This might actually register for you. The cost of mass shootings is 2.6 of the nation’s gross national product
https://everytownresearch.org/report/the-economic-cost-of-gun-violence/
It gets worse, it is already starting to affect tourism, because multiple nations are putting up, rightfully so, travel advisories because this country is that dangerous.
https://www.verifythis.com/article/news/verify/travel-verify/travel-advisories-warnings-from-other-countries-for-united-states/536-93e505b3-9872-4199-aa9b-a5d3a35b4ded
On a very personal level, I use skills that I obtained as a first responder decades ago, when responding towards gun fire, cover and egress. This is not a skill set that should be relevant when going to buy the groceries. However, it is extremely relevant these days.
This is not normal. By the way you started with a myth…and confronted with reality, you triple down.
This is not going to change until enough people in denial are personally affected by this, with a very preventable death or life changing injury in their direct family because, as Justice Berger put it, guns need to be regulated and the companies made liable, just as, oh your dishwasher manufacturers.