Yes some people will never get it and some of those people can be our own siblings. And they can be hardest on us and wound us the deepest. One would think it would be "us" against the alcoholic, being a team to master the chaos, but it's not. We all relate how we can to the alcoholic and the alcoholic manipulates and keeps us apart for their own reasons, at least in my family of origin. As you read through this forum you will see you are not alone and most of us have experienced these same situations.
Emotional detachment is what helped me get through those experiences, tempered with undeserved forgiveness, but not excusing behavior.