I ran into the same stuff after playing Navy for 4 and for some reason of temporary insanity joined the Army NG of my hometown.
It was just like HS again. The unit was going to get decommed and they let go back to the Naval Reserve.
The class nerd and jock will always be seen as the class nerd and the class jock as adults. The cheerleaders will still have their cliques regardless of what age and gravity did to them. the stoners will always be the stoners, the drunks the drunks and the rest. None of it changes and no one ever forgets who got caught doing what with whom, when.
It is why so many places are so dysfunctional. Many people stay stuck in that mindset and treat each other accordingly. It’s like a self fulfilling prophecy.