I used to run myself insane trying to "help" others (read: trying to control, set my own agenda, use them as an excuse as why I felt ragged inside, get upset when outcome wasn't what I wanted (even if that looked like the "right thing, it wasn't mine to decide or make happen)).
If (and when) I do that now, it DOES effect my marriage / relationship to myself / ability to function internally and externally, because I am not being real or honest with myself. It's O. of my dysfunctions (def. impaired functions) and hopefully we work towards being balanced and functional.
In relationships, I have to be careful not to get wrapped up in the results of my service / my end. If, for example, I give a girlfriend support through a breakup from an abusive relationship, I can't take it personally or feel betrayed if she goes back. If I help someone paint their house, and their kid draws on the wall, I don't get to see that as an attack. I do get to feel fulfilled by the process of offering support and assistance to someone who I love. No expectations. No small print. If I can't, or don't want to do that, then I butt out / take space. I get to place boundaries. I get to choose not to be the victim. I get to choose not to hold others responsible for the way I feel, react, and act. Those are my choices to make, and it's situation to situation. I do NOT have this down yet. Work in progress.
Anyway. I come with baggage. My husband knows that. He gets to let me (not to be confused with is-always-happy-to) work this stuff out. When my stuff gets in the way of our marriage (i.e. I have to go enable this person, and I want you to relinquish your boundaries so that I can be free to be a victim) he gets to call me on it. He also gets to have big feelings. He also gets to set boundaries. Ultimatums haven't been useful (i.e. it's me or your sister). Putting together strategies and negotiating are (i.e. you love this person. You give this person time and energy, then get depressed when she doesn't follow through with her healing, then you withdraw/feel angry and sad/take it out on me and the kids. It's hard to watch. It doesn't seem productive. I deserve to be treated with respect. I don't trust your sister or want her around our home. You're not ready to let go. What can we do to make our lives more functional?)
ETA (My husband get's to choose not to have a relationship with everyone I do, and vice versa. We also don't have to always agree with O. another. However, if there is an individual who threatens the other's emotional/physical safety, we should have the ability to not have them in our space, even if it doesn't seem rational. However, if we are setting that boundary to punish someone, prove something, or force their "bottom", I'd take issue. That's not setting a boundary, that's pushing an agenda)
We are, inevitably affected by O. another's relationships and lives. Being a team is the goal. Like the "Allegory of the Sun and Wind".
-- I'm not saying your neighbor does what I do. I'm just relating it to my own life and what's been effective/ineffective for us.