I know. It's often either preaching to the choir or it falls on deaf ears, though.
The thing is that many people seem to have this mistaken belief that just being able to own and shoot a gun somehow means they also have an innate grasp of the law, and what it means when it comes to determining reasonable and lawful actions and conduct during highly stressful moments.
Some folks who seem to go to great effort to choose some gun, ammo and holster combination can get a bit annoyed, and even confrontational, if they're asked whether they've actually prepared themselves for such situations by seeking to acquire professional training and knowledge in this regard.
The cost of getting some professional (and vetted) training - no matter the added cost of taking a day or two off work, and travel, lodging and meals - would seem to pale when considered against the likely costs of even the most affordable legal representation fees. (Let alone considering the potential for losing a job, because you're incarcerated for a while, and probably losing housing, some possessions, bank accounts, etc.)