I remember you posting about this friend, I think. I think we all of us have different personalities. For some people, this micro managing may work. For me, I can't stand it. Within 5 minutes I'm hysterical with how my son behaves. I think while you may be more tolerant and have more self-control, you may be more like me. It's not sensible to ask of ourselves what we do not have to give. Nor is it kind.
This is another way I need to accept the reality of things. To recognize my own needs and limits, and to act accordingly. Our adult children will consume all of the air and resources that we give them. Including our life force, our serenity and our confidence. It is my own responsibility to protect myself. And to not give what I don't have. Or don't want to give up.