I'll tell you this, I've got my two hands and a hell of a will to live. If some SOB puts a gun on me in my own home and tells me lie down, he can most certainly "go fornicate" I ain't letting him kill me easy, hes going to have to work for it.
I went to the range this weekend... probably shot about 500 rounds. My finger didn't even break a sweat.
What I'm saying is that it doesn't take much to pull the trigger. So, he won't have to "work for it" all too hard if he's already decided to shoot you.
+1 for situational awareness. +1 for being ready to defend yourself.