I thought, all my life, that I couldn't own a gun safely, that no one could, really. Guns were dangerous and icky. Even after I realized that the Second Amendment was not quite the shriveled, antiquated appendix I'd been taught, for a couple of years or so I still wobbled around with the training-wheel comfort of believing that while not all gun owners were necessarily gap-toothed red-necked fascist militia whackos, I myself ought not to own firearms. I was too clumsy and careless, and guns were still dangerous and icky.
Just before 9/11 I woke up to how quickly my liberty was eroding, and in a fit of anger and defiance started saving for a handgun while training with rentals. (Thanks to Harry at Texas Shooters Range here in Houston.) When I actually bought one (to the horror and confusion of my friends and family), having it around the house, carrying it in my car, talking about it, showing it off, and of course shooting and maintaining it, taught me what I could not learn from books, magazines, classes, or even Usenet:
It taught me that freedom takes practice.
I thought I'd practiced. I'm as full of opinions as the next guy, and not shy about passing 'em out to anyone who'll listen. I read banned books and underground comics. I've walked the picket lines and hung out with undesirables. A preacher's kid, I pointedly don't practice a religion. I've done stuff that Wasn't Allowed.
But when I got a gun, I discovered it had all been safe, padded, wading-pool-with-floaties dabbling. After near on to fifty years, I finally started to grow up. If my Grands are any clue, I've still got twenty or thirty years to work on it, and get to be something like mature by the time I go senile.
It's not just that rights are useless if they are not exercised, not even that rights must be used or be lost. It's that exercising your rights, constantly, is what instructs you in how to be worthy of them.
Being armed goes far beyond simple self-protection against thugs or even tyrants -- it's an unequivocal and unmatched lesson that you are politically and morally sovereign; that you, and not the state, are responsible for your life and your fate. This absolute personal sovereignty is the founding stone of the Republic. "A well-regulated militia" (where the militia is "the whole people") isn't just "necessary to the security of a free state" because it provides a backup to (and defense against) the police and the army. More importantly, keeping and bearing arms trains sovereign citizens in the art of freedom, and accustoms us to our authority and duty.