I never have used my gun for self defense. And I hope and pray that I never will have to. Given where and how I live, there's a pretty good chance that my prayers will be answered.
That said, if some scumbag wants to rape my wife, you're darn right I'll pull the trigger.
Having taken LFI-1 and LFI-2, I'm well aware of the liabilities. I won't use my gun to protect my car or other property -- that's what insurance is for. But I will use it defend myself and my wife from threats of death or grave bodily injury.