I have two thoughts - first, this guy is a perfect illustration of the devaluation of a college education. Anyone can get one today, even Mr. Green, who seems to have difficult forming a complete sentence, on any topic more complicated than his own name.
Also, if Wiki is to be believed, Mr. Greene was administratively separated. I haven't heard anyone ask him why he was separated from service, nor have I seen it explained anywhere.
Had a buddy in college who dropped out a semester to go in the Air Force. He didn't intend for it to be just one semester but he became violently ill eating food in the mess halls.
The Air Force "administratively separated him"
You can't be in the military and also be UNABLE to eat the food. My buddy really, really, really wanted to be in the Air Force BTW.