There's the story about the guy who says he was the hardest working man in Vietnam, and then when pressed about what he did, he states he was a trucker to the great surprise of anyone listening.
When asked why he thought that, he says "well I was the only one."
https://vietnamnews.vn/sunday/features/947180/female-drivers...
The joke is that everyone else he went to war with was claiming to be something else, so he must have delivered all the supplies himself.
The response is interesting to me, because having fought in a war, though I am not a US veteran -- I instantly got it. And the place I heard it from was more veteran dominated, and everyone instantly understood/appreciated the joke.