or you could try to draw on someone who is just faster and better than you, piss him off, and he kills you and every other person in that store, because you wanted to be in the news to prove that a good guy with a gun can make a difference...and you were right, you made a difference in that robber's day, the clerks day, your own day, and the days of everyone else you just got murdered...
I don't know you , so i can't state this as a fact, but i'm relatively certain no one elected you to protect a fucking thing...don't appoint yourself saviour, you haven't even had the crappy training most cops get.