When I was around 12 or so, my dad was in the army and worked on anti-aircraft systems. One Saturday he needed to get or do something at the shop so he drug me along for the ride. Both of us in our plain clothes. We walked up to the shop, 2 guards patrolling, he said hi, pulled out his keys and opened the door. I was in awe of what I saw inside.. 15 M163 Vulcan self-propelled anti-aircraft guns all in a line. We piddled with some things, he started one up and made sure to tell me repeatedly dont stand in front of this.. (the radar).. and after an hour or so we left.
Almost to the car, he said.. "you remember those two guards?" "Yes.." I said "I didnt know them from Adam. You can get away with anything if you look like you know what you are doing."
A lesson I have remembered all my life and used on more than one occasion.