The Johari Window

The Johari Window sounds somewhat esoteric until you learn that it was devised by two men called Joseph and Harry. Despite this quaint naming, it is, in fact a very useful way of understanding something of how our self may be divided into four parts that we and others may or may not see.
The Basic Johari Window
Below is a diagram of the standard Johari Window, showing the four different selves and how the awareness or otherwise of these aspects of our self by others and ourselves leads to these four categories.

The Public Self
The Public Self is the part of ourselves that we are happy to share with others and discuss openly. Thus you and I both see and can talk openly about this 'me' and gain a common view of who I am in this element.
The Private Self
There are often parts of our selves that are too private to share with others. We hide these away and refuse to discuss them with other people or even expose them in any way.
Private elements may be embarrassing or shameful in some way. They may also be fearful or seek to avoid being discussed for reasons of vulnerability.
Between the public and private selves, there are partly private, partly public aspects of our selves that we are prepared to share only with trusted others.
The Blind Self
We often assume that the public and private selves are all that we are. However, the views that others have of us may be different from those we have of ourselves. For example a person who considers themself as intelligent may be viewed as an arrogant and socially ignorant by others.
Our blind self may remain blind because others will not discuss this part of us for a range of reasons. Perhaps they realize that we would be unable to accept what they see. Perhaps they have tried to discuss this and we have been so blind that we assume their views are invalid. They may also withhold this information as it gives them power over us.
The Undiscovered Self
Finally, the fourth self is one which neither us or nor other people see. This undiscovered self may include both good and bad things that may remain forever undiscovered or may one day be discovered, entering the private, blind or maybe even public selves.
Between the Blind and Undiscovered Selves, are partly hidden selves that only some people see. Psychologists and those who are more empathic, for example, may well see more than the average person.
Four personas
Associated with the Johari Window, we can define four different personas, based on the largest 'self'.
The Open Persona
Someone with an open persona is both very self-aware (with a small blind self) and is quite happy to expose their self to others (a small private self).The Open person is usually the most 'together' and relaxed of the personas. They are so comfortable with themselves they are not ashamed or troubled with the notion of other people seeing themselves are they really are.
With a small Blind Self, they make less social errors and cause less embarrassment. They are also in a more powerful position in negotiations, where they have less weaknesses to be exploited.
Becoming and Open Persona usually takes people much time and effort, unless they were blessed with a wonderful childhood and grew up well-adjusted from the beginning. It can require courage to accept others honest views and also to share your deeper self and plumb the depths of the undiscovered self.
The weaker side of the Open Persona is where they understand and share themselves, but do not understand others. They may thus dump embarrassing information from their Private Selves onto others who are not ready to accept it.
The Naive Persona
The Naive person has a large Blind Self that others can see. They thus may make significant social gaffes and not even realize what they have done or how others see them. They hide little about themselves and are typically considered as harmless by others, who either treat them in kind and perhaps patronizing ways (that go unnoticed) or take unkind advantage of their naivety.

The Naive Persona may also be something of a bull in a china shop, for example using aggression without realizing the damage that it does, and can thus be disliked or feared. They may also wear their heart on their sleeves and lack the emotional intelligence to see how others see them.
The Secret Persona
When a person has a large Private Self, they may appear distant and secretive to others. They talk little about themselves and may spend a significant amount of time ensconced in their own private world. In conversations they say little and, as a result, may not pay a great deal of attention to others

Having a smaller Blind Self (often because they give little away), the Secret Persona may well be aware of their introverted tendencies, but are seldom troubled about this. Where they are troubled, their introversion is often as a result of personal traumas that have led them to retreat from the world.
The Mysterious Persona
Sometimes people are a mystery to themselves as well as to other people. They act in strange ways and do not notice it. They may be very solitary, yet not introverted

As the Mysterious Persona knows relatively little about themselves, they may be of low intelligence, not being able to relate either to themselves or to others. They may also just prefer to live in the moment, taking each day as it comes and not seeking self-awareness.
Some forms of esoteric self-developments seek to rid oneself of concerns about the self in order to achieve a higher state of being. They may deliberately enter states of non-thinking and revel in such intuitive paradoxes as knowing through not knowing.

Content taken from changingminds.org