Is anyone ever paranoid about being involved in a violent situation? Such as one of the recent shootings?

There is always so much scary stuff going on in this world. I tend to always be looking over my shoulder, always checking to see what that guy is pulling out of his coat..and always thinking what would I do to help myself in a bad situation. Like the recenting shooting in the mall. What a scary thought! To be just shopping with your family and then be in the middle of gunfire!! I was just wondering if anyone else is always looking over their shoulders too! I mean its a scary world out there!! What would you do if put in a situation like that? It only takes one person with the right decision to save lives!