My dad is an auto mechanic, so he's often working under a car, hands covered in grease and in uniform, everything obvious.
And yet he gets these stupid people who walk up to him and ask, "Do you work here?"
My dad actually snapped back, "No. I'm just some guy who wandered in here and decided to fix cars for the hell of it."
And the customer puffed up and screamed that my dad "just lost himself some business."
My dad, ever the awesome guy he is, just went back to work, leaving the moron sputtering.
Sometimes the service industry is just as bad as Retail Hell.