This mask, i.e., the ad hoc adopted attitude, I have called the persona, 79 which was the name for the masks worn by actors in antiquity. The man who identifies with this mask I would call "personal" as opposed to "individual." [801] The two above-mentioned attitudes represent two collective personalities, which may be summed up quite simply under the name "personae." I have already suggested that the real individuality is different from both. The persona is thus a functional complex that comes into existence for reasons of adaptation or personal convenience, but is by no means identical with the individuality.
— Carl Gustav Jung
Jung is careful here to say the persona exists "for reasons of adaptation or personal convenience" — not as error, not as failure, but as a functional response to a real demand. The world requires a legible face. You learn early which face gets you through the door, which one keeps people close, which one makes the room safe. The mask is not the problem. Identification with it is.
What happens in that identification is subtle enough to miss: the individual stops being the one who wears the face and becomes the face itself. The private life — whatever lies beneath the mask's logic — gradually loses reality. Not through any single decision, but through the accumulated momentum of being received as the persona, rewarded as the persona, known as the persona. The convenience becomes the cell.
What Jung calls "individuality" here is not a stable object waiting to be recovered. It is whatever in you has not yet been organized into serviceability. That unorganized remainder — the part that doesn't fit, doesn't perform well, doesn't translate into legibility — is precisely what the persona was built to manage. The recovery of it is not a softening of the mask. It is the willingness to be unknown, temporarily, in the space where the mask no longer fits.
Carl Gustav Jung·Psychological Types·1921