As mentioned before BPD can be brought under control and even cured with the right therapy (I suspect that is why you no longer have BPD traits Wander - you have worked through it and come out on top - well done to you). As I have mentioned many times before, I know personally at least 20 people who now live med and mood swing free after committing to DBT and therapy specific for BPD.

PTSD is a hard one too as it can mimic bipolar and can be comorbid. I suffered from PTSD but have that under control now and my moods became more stable through time and therapy. I was only triggered by certain smells, memories, nightmares and anniversaries of the occasion which triggered anxiety and depression for short amounts of time (ie 3 - 4 weeks). So I could differentiate between that and a BP swing as my BP swings last for much longer. In saying that, in the time close to the event my moods would last much longer but with therapy they quickly shortened and I was able to distinguish between a BP mood shift and PTSD triggered mood shift. I no longer have mood episodes caused by PTSD.

You can certainly have triggers for moods in BP also, but the difference is how long the mood lasts and what the trigger is. For example stress, any stress, good or bad, sets of my BP. But something like someone cutting me off in traffic or ignoring me or "abandoning" (for lack of a better word) me or interpersonal problems does not set off a mood episode as it could for BPD.

As mentioned in the article the correct diagnosis will help you get the correct treatment. It makes me sad to see people struggling so much but have been labeled wrong and are getting the incorrect treatment (not referring just to those on this site, also my experiences as an inpatient and working with the mentally ill).

Jacky your question about winning the lotto - this is a question I always got on admission in my younger days, if you won the lottery what would you do? My answer was always donate it to charity and kill myself. That is how they tested to see if my mood was reactive to external stimuli.

Also remember not every mood is a BP mood and you may have just been feeling a little low but not completely depressed and the lotto win was enough to lift you out of it. Unless of course you are now exhibiting hypo/manic behaviour - that is a telltail sign that it is not a BP mood, but one triggered by an external event and not likely to last.