The “15” means 2015 as is SOP with military exercises. Any active duty servicemember would know this. An ROTC cadet ...not so much. And shouldn’t you have graduated by now and be in service? So what’s your MOS and where have you been?
Probably a stolen Valor POS. He doesn’t seem to know a whole lot for a Butterbar. and as I said upthread, if he’s legit, his instructors should be court martialed for incompetence.