Untill we are faced with that situation we don't really know if we will pull that trigger. If we do, even if we are totally in the right, it will scar us as well. Alive and scarred is still better than being dead though!
Scare a man and he'll pull the trigger. Trust me. Fear does profound things to you psychologically. If you think you're going to die if you don't pull the trigger, you will.
I have read people getting sued by the intruder b/c he was shot. I dead intruder cant sue. Practice shooting just a little so your more comfortable and use REAL ammo