Guns aren't always the answer, in fact, using a firearm to defend your life or the life of another is ALWAYS the ABSOLUTE LAST resort. It starts with being prepared. It starts with knowing there is evil in this world, and there is no way to predict when, where, and how it will strike. It starts with having locked doors, having an emergency plan with your family, knowing where your exits are when in public, carrying at least a pocketknife and a flashlight everywhere you reasonably can. I carry a pistol everywhere I go except for work. I train and practice with it, and at night it sits holstered on my nightstand next to my flashlight.
It's not paranoia, I have never been the victim of a violent crime - and hope to never be. I don't want to take a life. But I know damn well the police aren't going to save me from a carjacker, a rapist, a mugger, or a junkie, and I know damn well I'm not going to cower under the blanket if the glass breaks in the middle of the night.
The what ifs can go on for days, but there's no arguing that it's far better to have and not need, than need and not have.