Such a statement can also be beneficial during other interactions, such as those with police officers. Not everyone can be a Marine, and if you are, say so. A Marine bumper sticker in the window and dog tags hanging in the rearview mirror can also go a long way. Marines are everywhere. But not all Marines are that easily recognizable.
Some garb is understated in in black, silver, green, or camouflage.
Designs range from a simple Marine Corps emblem, to the Tasmanian Devil, or a leatherneck tattoo, to an elaborate display of Marine weaponry. Marines will proudly inform you, and anyone else who happens to be listening, that they were in the Corps. Their comment may have no connection with the present conversation or situation, at least not to the common ear, but anything can, and will, rouse memories in a Marine. You could be in a crowded doorway, taking refuge from a storm, and a 40-something gentleman tells you he doesn't need an umbrella because he was a Marine, and compared to the monsoons in Southeast Asia or Okinawa, this downpour is just a sprinkle. Or the moving man mentions in passing that he developed strength and endurance in the Corps.