I'm glad I don't need a gun to make me feel safe in this country, because I don't have to worry that someone else might have one.
That's the misconception. There is strong evidence suggesting that it's places like gun free zones and locations where they are heavily restricted/banned that you should be most concerned that someone else will have a gun. Bans only remove people's ability to defend themselve with one if they would otherwise choose to. Criminals are more likely to target people/places without guns than where people may have one to defend themselves.
Not a misconception in Australia. I can honestly say that I have not ONCE felt worried that someone might shoot me here. "Criminals" (The way it's being said in this thread makes it seem like you should know who's going to be one from birth) aren't rampant on our streets with guns blazing every year, we don't have major school shootings, we had a loon once and upped the gunlaws and that seemed to work very well in Aus. So whoever these criminals targeting my country because of its laws are, they're doing a terrible job. As for your gun law-ier states, they're still pretty lax (The mother still had a gun, if she could have one, chances are someone else at the school could have too) and people who wanted could probably just meander to another state to pick up a gun, right? Also, these instances aren't really chosen for their location being less occupied by gun-carriers, but for personal ANGRY reasons. Had this kid been in another state with less gun laws, I dare say he still would have gone nutty.
Also, I believe there are more, and better ways to defend yourself and the population than with with a gun. Were I to pull one out at someone who pulled a gun on me, I'm sure as heck that it'd make the chance of them shooting me first a lot more likely. HOWEVER, with our
TERRIBLY SOCIALIST/sarcasm free mental health services and decent checks on people buying guns (I'll have it known that I live 5 minutes from the biggest gun store in the country, we still have guns here), by being sensible (Not wandering into dark alleys at night in seedy areas, traveling in herds, going to reputable areas, not provoking anyone who may be dangerous etc) and by being decent and trusting
enough of each other we seem to get by just fine in this country. Yes homicides and other crimes still happen, they always will, but as far as I can tell our gun laws have made this country a lot safer.
Unfortunately it's so ingrained in American society that you NEED a gun because the gun companies got their advertising so right that I doubt there's any way to fix the problem over there.

Everyone already has a gun, so IMO it's too late but that doesn't mean that the govt. should just sit back and wait for everyone to kill each other, does it? Gun laws alone aren't going to be enough, but it's a step.