I don't know if this one has been mentioned or not but I used to use it all the time:
As pax are boarding you get the standard "Are you old enough to fly this thing?"
My response, "Actually no, but it's Bring Your Kid to Work Day and that's my Dad up front."
I also had a pax in DEN berate me after the leg from Sheridan, Wyoming because "you kids had no idea where you were going, you flew the wrong way outta Sheridan then finally turned around and went the right way!" Imagine me trying to explain an Obstacle Departure Procedure that requires you to go north to the VOR then turn...