Back when I was a rookie cop, during the first night I was allowed to patrol alone, I pulled over my first car. I walked up to the car, picturing myself looking very professional. THe woman in the car said in a very timid, Dolly Parton-like voice "What did I do, Officer?", and i said in my best serious voice "Ma'am, do you realize you just went through a sop stign"? I kind of lost my composure then, and just asked her to be more careful in the future and let her go.

I also once informed someone that I had pulled over for a traffic violation that he also had an inspired expection sticker on his car.