To learn mind set you have to practice it every day. That means being more ruthless, more brutal less trusting and quicker to use violence than the other guy.

You sound there like you're advocating being a bit thug-like in your approach, and I don't think that's what you meant, or hope not.  As the good guys, we have to act like good guys 100% of the time, and, perhaps unfortunately, wait for the bad guy to make the first untoward move.  But once the fight is on, at that point we go full tilt wolverine to save ourselves and protect our loved ones.  That's where any and all civility on our part is out the window and Hoyle be damned. 

But we can't "practice this everyday."  Most of us aren't dealing with criminals on the street every day or dealing with convicted thugs in the prison system everyday.  We have to be wary of course, but we can't go starting fights--not ever, especially as legally armed citizens. 

What we can do is keep it in the forefront of our thinking at all times, and try to stay mentally prepared for it.  Having the tools, learning how to use them, and being physically ready are all important, but without the mindset to fight to the very last, they are all worthless.  That's what I was trying to say.