Well, its simple, u not allowed to bear guns without a license, and for that u need to be at least 18, because before that age very few can have real maturity anyway. and to get a license u have to prove yourself not insane, u have to be affiliated with a gun club and/or work in security sector (from what i remember)
i dont see where the problem is with these regulations.
in fact its the only way to be sure the person with a gun wont be totally insane like its too often the case in countries where there is no gun laws or very little.
u can say we have less freedom, we dont see it as freedom, we see it as a cause of murders, and by looking at "death by gun" numbers, i guess we are right.
its like driving a car, if u are insane or too young or anything u can cause horrible accidents. so u need a driving license
but obviously we have less guns in the streets than u have
so i can understand some people wants the feeling they can "try" to protect themselves, in reality more people cant and therefor lots are dying by guns.
this story could also be totally different, like the bad man see a kid with a gun and then decided to shoot, while if the kid didnt have a gun he wont shoot.
who knows
in fact the story is most of the time very different like numbers are saying.