"Introductory Self"

The term "introductory self" is one that is rather new to me; I had never heard it until a few months ago, and it is something that has been on my mind quite frequently ever since, especially when meeting new people. My significant other used it to describe the person they were when I first met them versus the person they were at the time ("introductory self" versus "real self"), and she is still the only person I have ever met to use that term. In short, the "introductory self" is the side of a person that others see upon the first meeting, or, the best version of themselves.

You see, when our relationship started falling apart, I asked Josie (fake name for privacy reasons) where the girl I had fallen in love with had gone, and to this she responded, "You fell in love with my introductory self. That's not me. This is who I am."

At that point, my relationship had seen every form of disrespect possible from my girlfriend. She had given her number to other girls simply because they were cute and bisexual; she had agreed to be other people's dates to romantic functions; she had chosen a roommate that she was attracted to; she had told me I was no more important to her than anyone else; she allowed people to flirt with her right in front of me; she frequently told me to just shut up; she had even kissed another girl while being with me. And the list goes on. But I stayed with her because I loved her.

The thing is, though, the girl I fell in love with was apparently her "introductory self." She was so sweet, so patient, so caring; she could always make me smile when I was sad. She would pull back from people who made advances on her out of respect for me, she would never hesitate to reassure me of her love for me...

So my question is, is one's "introductory self" simply them putting their best foot forward, or is it being fake, especially if it goes on for nearly six months before the façade drops and they turn into a completely different person? I guess the answer is all up to who you're asking, but let's look at this from an unbiased standpoint for a second:

Upon meeting someone new, the mind likes to fill in the blanks of who that person is. It's normal for most people to put their best foot forward, so it's also normal that the majority of the time you meet someone new, you like them at first. They've only shown you positives about them, and your mind has filled in the rest with more good, so what's not to like?

Then, as you get to know more about them, those little details that your mind made up get changed as you learn the truth. That's when you may start noticing things about them that you dislike. At this point, if the relationship is romantic (or on that track), you just have to hope you still like them for who they are.

Now let's discuss the other possibility: being fake. When a person is being fake, they're pretending to be someone they really are not just to appeal to others. This can be anywhere from changing their actions, language, attitude, etc. to something unauthentic.

So, to reiterate, is one's "introductory self" just them putting their best foot forward, or is it them being fake? Again, I guess it's all up to who you ask. Is it possible that I had just been blinded by the light of Josie's best-foot-forward-created-fantasy until I was forced to accept it wasn't true? Of course. But is it also possible that she had fooled me into thinking she was someone else until she couldn't keep up the act anymore? Also, of course. And seeing as she's the only one I've ever known to use the term "introductory self," and our relationship is long over, I guess we'll never know which meaning that term truly has.