I've read lots of different versions of this, there's even sociological explanations of it too in microsociology or earlier in Erving Goffman, one of my favourite theorists, who studied asylums, stigma and the presentation of the self in everyday life, there was a brank of pscyho-analysis, I think it was called ego psychology but I could be mistaken, which talked about the true self and the social self or facade, considering the dynamic conflict between each to be the source of mental suffering and striving as opposed to Freud's ego, id and superego, though it was not necessarily a case of the "phony self for others" as it mattered just as much to the whoever had constructed it, importing aspirations, ambitions, hopes and dreams which with the passage of time may be less and less realistic or feasible or attainable.
It interests me that there's this tripartite idea of the self or personality which keeps arising in humankind, Freud is a big proponent of it, Jung went beyond it with the archetypes into dozens or more facets of a single self, although it had premodern precursors, Erasmus talks about a tripartite self, a spirit, a body, a soul, there are others who he read in turn and right back to the more mystical sides of the abrahamic religions with their own versions of God, Holy Spirit and Christ (or equivalents, I'm not up on Sufism, Kabbalah, hasidism etc.). However, not to get side tracked.
I think that often there is more consistency that people realise, perhaps during particular phases of your life you may spend more time thinking about what you project and what others perceive you as being, such as adolescence or at times when social currency matters a lot, I think it has contexts later in life too, for instance work, if a lot of people in a particular workplace are like that and it becomes the governing work culture (which I dont necessarily believe it should but it objectively does).
However, that said, my own view is that you may not be acquainted with a facade when you meet someone to begin with and then discover the "real them" with the passage of time but rather what happens is you may experience a growing attachment and with that a willingness to comprehend them in greater depth, with more insight about a person what at first appeared superficial or incomprehensible or paradoxical about them makes more sense the more you know, I dont believe that is necessarily the same as facades or false selves versus the real them.
Personally too, I would add that I do believe in the individual and social conscious/unconscious divide, a lot of people are unawares of how they act, are perceived etc. or their self-perceptions are wildly inaccurate or coloured in some way, I think the totally unconscious and unaware individual is a torture for a lot of those who have to have regular contact with them, they are generally stressed themselves and good at stressing everyone else out too. Erich Fromm wrote towards the end of his life about how he felt very concerned by how many people he felt had not depth of character or seemingly no character what so ever, he said this wasnt an ethical comment, he didnt not mean they were dishonest, he meant that they seemed to lack a self and were just marketing themselves however they could, conforming even when they thought themselves non-conformist etc. I think that's an interesting thing, especially since he did not live in our present age of distraction, misdirection and confusion which I think has only compounded things.
Although that said there people who try to manage their relations with others through deceit, who are vindictive, who do have more faces than a town clock. In the main those are pretty damaged individuals who have learned and continue to apply some pretty abnormal explanatory styles and relating patterns, usually when you get down to it they've got terrible underlying feelings of being inferior and all sorts of narcissistic defences deployed to the hilt. It'd be easier for most normal people who've found them out if those same individuals didnt appear to as successful as they do in life but as the saying goes "long runs the fox, though its still vermin".