As Blackbelt says, there are different ways to learn things.
In this scenario, let little Johnny two-step stew over his vulnerability from the ravaging hordes. It should put a pit into his stomach, and maybe make him rethink his life. In a world where one can get cheap, used guns for under $200, there is no excuse. I'm speaking of handguns of centerfire caliber. You can get 12ga shotties under 200 all day long in normal times.
If you lend a gun, and he shoots anybody with it, your liability would go to the moon. They'd go after him, and you. And what could you say? What training did you do? How competent did you find him to be? Had he ever done CQCXYZ training in order to know when and when not to shoot? Did he shoot a 'ghoot baway?' (He a ghoot baway, just turnin' he life aroun') Or, God forbid, does he shoot someone in the back or a woman/child, or do stray bullets hit bystanders.
Say, hey, good luck man, and you really need to get a gun soon.
A smart man doesn't try to put his seatbelt on in the middle of a crash.