OK, so I've established a new rule.
You do not get to complain about what a terrible situation you are dealing with, if I have been warning you for a long time that this situation was developing, and would continue and worsen.
If you ignore me, you do not get the luxury of moaning and complaining to me, I will not give up my precious time and energy to you. I have a limited supply, and I choose not to waste it on nincompoops.
Seriously. I know everyone has to learn their own life lessons, yada, yada, yada. I simply cannot give more of my own limited resources to listen while you complain about the choices you made. I would be happy to commiserate if the situation were out of your control and just happened to you. But when you create the situation, after I've explained to you the perils of that course of action, you're on your own.
And while my sister will never read this, I had to write it. I think mostly it's a reminder to me that I am not obligated to let her spew her disfunction all over me. I didn't create her problems, and I could have, in fact, prevented some of them, and would gladly help her work through some of the others. But allowing her the time and space in my life to dump all her negative feelings has to stop.
So this is a reminder to me. I have a new rule, and for my own sake, I need to follow it. I have got to protect myself, and the best way to do that is through establishing this boundary and sticking to it.
Wish me luck.