Oh for God's sake.  I served in the Marine Corps as an AAV crew chief (1833) and small wpns repairman for 8 years, and I could give a crap less what someone calls me.  Former Marine, Ex-Marine, old jarhead, defender of our freedoms, that old cranky guy; none of it matters.  Usually the people that repeat this old bit of fiction were never in the military and are attempting to gain some sort of celebrity-by-assocation, IMO.  Either that or they have a stick up their a** that the First Sergeant needs to remove.