Been there! He's 21, he a kid. And he's also a grown man. Yeah, doesn't make sense right? He was out there on his own, doing what he pleased. Now he's home with his tail between his legs, but he's back with all that freedom he had, if that makes sense. I think maybe (and this is just my thoughts on it) his resistance to your advice or commentary is that push/pull of man vs boy, freedom vs back under Mommy's roof.

I don't really have any advice. Granted, I wouldn't take any crap from him either, LOL