You could be missing the point of my post

Anyway, as far as said viewpoint though, yes - virtually everyone could be susceptible to having BPD. I've heard it being described as: "we shouldn't look as though we are diagnosed with a disorder, we are just in a different place on the spectrum, and that we have the ability to slide to another place on that spectrum."

However, as tara4bpd.org puts, it IS when stuff becomes too "extreme":

"Personality includes those aspects of a person's thinking, moods and behavior which affect his or her relationship with others. Differences in personality style (traits) add color and variety to relationships but may become too extreme, inflexible or maladaptive. These traits can significantly impair a person's ability to function. When a person is not able to deal with people or problems constructively or not able to adapt to changing demands of the environment, he or she is said to have a Personality Disorder."

(And yes, the typical wonder of "What is 'normal' anyway?")

I hope that could clear things up