Once upon a time, I worked for a guy we'll call "Ken", because that was his name.
Ken was a real character, and I don't necessarily mean that in a good way. He had a very active fantasy life which he tried to share with the rest of the world.
In Ken's fantasy life, he was an SF sniper in Vietnam. He claimed that when "his sergeant" tried to take his beloved M-14 away and replace it with one of those cheap Mattel toys, Ken threatened to kill him, and was allowed to keep his M-14. (Which is an odd action for an eleven-year-old, that being about Ken's age when the M-14 was replaced in front line units.) Needless to say, Ken's unit was wiped out, leaving him the sole survivor, not once, but twice. And both times when he rolled all the bodies of his buddies over, they all had a jammed M-16 with a cleaning rod stuck down the barrel in their hands.
Ken's grandpa was an even bigger hero, having served in the USN during WWII, winning the Medal of Honor three times, and having three aircraft carriers sunk out from underneath him.
Needless to say, one of the most important tasks of myself and the other employees at the shop was to keep the owner from interacting in any way with the customers, lest he entertain them with his tales of imaginary derring-do in a fantasy Saigon, where he was apparently all the time stabbing pimps to death with his Gerber for vaguely-defined reasons.
A guy at GeorgiaPacking.org seems to have discovered an apparent relative of Ken's at a Fun Show who not only has the stories, but also decided to get the costume to go with them. (And yes, that MP badge does count for "impersonating an officer" under certain circumstances...)
(H/T to WRSA.)