This is an interesting story with many excellent examples I came across
For people with this disorder, small problems explode into catastrophes, friends become enemies, love turns to hate – often with breath-taking speed. Relationships crumble, jobs rarely last. And their families are along for the ride.
The small problems exploding into catastrophes hits home with me. One thing that people need to understand about the disorder is that Borderlines will constantly test your boundaries. From day one you're boundaries are being poked and prodded and tested to see how strong you are. If you show any weakness with a borderline you are lost.
At the same time, if you are firm with your boundaries, be prepared to lose the relationship/friendship forever if you hold firm. An example is when my ex told me would call me on a specific day. She made a specific promise. As usual that day came and went without a phone call, so when we spoke next, I asked her about it. A person in a normal healthy state usually isn't going to blow someone off without good reason, and if they do, they usually apologize and attempt to rectify the situation. That is NOT how it works with a Borderline.
They will create an excuse, usually imagined, that is designed to create guilt and pity for even questioning their behavior. For instance they were "too busy" and "things are going bad right now. It was too hectic". All designed to make you wilt in enforcing your boundary. My ex is a MASTER at this tactic. If you even question a little why they were too busy to dial a phone number for two days as promised you will be attacked viciously and personally, depending at what stage the Boderline Rollercoaster relationship has currently evolved into.