You identified the problem with your observation that dealing with him is like dealing with a small child.
Suggest to a kid they should put a jacket on because it's cold outside.... They know better.
Suggest to a child that they need to get to bed early or they will be tired and grouchy the next day.... They know better.
Suggest pretty much anything to a child.... They know better.
And so it is with alcoholic folk..... They know better. Always.... Just like little kids.
Suggest something useful to a mature, well adjusted adult..... They usually listen or take the hint.
Kids and alchies.... Same thing, different body size.