...But the thought almost made me laugh out-loud, dispelled my brief anger, and so I simply ignored him. Some of the people standing in line heard him, including the cashier, and they gave the idiot some pretty disapproving looks.
my read about what you wrote is different from some. Your reaction was "to ignore" the guy, which doesn't strike me as extreme. Your feelings are different from how you reacted. What strikes me as a mistake (one i have made countless times) is the guy was presumptuous. He made one assumption, then after finding out he was wrong, jumped to another conclusion about you. We don't know if he would of thanked you for your service had you answered you were a vet, he could just as easily have been just curious, or wanted to tell you about his experience in Viet Nam, or_____________________.
i know what it means to be born outside the cultural norm (i'm gay), but that is not something that is readily (visibly) apparent to just anyone standing in a grocery store line. So i cannot relate to how you might feel or the myriad reasons why you might feel that way, but i can understand if you explain.
Put another way, what if the guy had been behind a black person and asked the question: "are you from Africa?" And upon hearing the "no" answer, immediately responded "your mom must have slept with a black man." To me it's not just a social faux pax. If the guy was really interested in you, he could ask you to tell some of your story instead of trying to guess at it.
One can take that different ways, depending on perspective, but i think they're pretty intimate comments/questions to be posing to a stranger in a check out line.