You go Girl! Love the Yoga Instructor idea

But to answer your question, there have been several

for me. I'm on these boards because my SO has an uBPDxw.
The first was Googling "Chronic Lying" and discovering BPD. The shoe fit like Cinderella and her glass slipper!
The second was finding this site with all the great tools and people with similar experiences here.
The third was recognizing and dealing with my own anger and anxiety.
The final thing was radical acceptance. My SO's ex was gonna do and say what she was gonna do and say.
I knew my SO and I had both finally arrived at a place where she couldn't push our buttons anymore, when she took both girls out East to deliver her oldest daughter to college. She took the younger daughter too, it was during dad's time and she was to be back in time to be back at school the following Monday.
Sunday afternoon we receive a call from mom that they missed their flight home due to traffic. Still cracks me up to this day... .did you know that Burlington Vermont has bumper to bumper gridlock traffic on Sunday? Who knew?

Anyway, the old me would have been furious. She was cutting in on my SO's time with his daughter, daughter was going to miss school, the old me might have even wondered if she was trying to kidnap their daughter. Instead my SO just told her to email him her new itinerary and we went back to eating our lunch. We learned to not feed the drama, to get off the triangle, and let her deal with her own stuff. That yes, they might be home later than planned but there was nothing we could do about it and getting angry wasn't going to improve anything.
I do want to add that since being on this site I have had some personal aha moments about myself that don't relate to my SO or his ex, just some good realizations about some of my own behaviors, patterns and insights into myself.
Great Question
Pina colada it's gonna be interesting to hear other people's responses.
Panda39