It is not certain at what stage of development when one becomes aware of self.  For some it may never happen.

The structure of self.

Each being is composed of three main entities.  The body or physical being.  The mental, the brain or the intelligence.  And the illusive spirit.  This my resemble the Christian concept of the Trinity or it may explain the concept of the Trinity's origin. It does shead light on the unique quality of all creatures.

If you were going on a blind date you would obviously want to know several things (not counting money maters) about the individual.  First you might ask about the physical appearance, height, weight, eyes, hair, attractiveness etc.  Next you might want to know where on the intelligence level between genus and imbecile they fit.  The last thing though you may sense upon meeting is the least tangible quality.  What is the nature of the individual, kind or mean, loving or cruel, good or evil: what kind of spirit do they posses.   These three factors are independent of each other but are inseparable  aspects of each being, be they human or animal or God.

One other example.  Some dogs are smart (brain).  Some are dangerous (spirit).  Some are down right scruffy ugly (physical).  These three independent qualities are the trinity of characteristics the comprise every creature probably down to even worms.

Everyone is schizophrenic

If you are mentally solving a problem, you are a thinker.  If you expound in public discussion you are a philosopher.  If however you are talking to yourself on these matters and are overheard by others you are idiot.  A very subtle difference with very different ramifications.  But: who are you actually talking to when you talk to yourself, when you weigh the pros and cons of a situation,  when you analyze a problem, when you reach the eureka moment of discovery?  Self is meeting self.  This can be a beautiful process or it can be terrorizing.  It becomes very problematic when you perceive the person you are communicating with as a different person or being, this is classic schizophrenia.

What if you discover that you don't like yourself.  What effect does it have on your spirit (self image) if you judge yourself inferior to what others around you perceive as beautiful.  What if you think of yourself as mentally inferior.  What if you look inside your very being, inside your soul and see it as ugly. 

Understand self

The first step in understand self is to be aware of the three separate major aspects of ones being.  Physical, mental and spirit.
The next step is to determine which is the most important.  If I loose an arm.  Am I any less me than before?  Though I have a handicap I am still me.  As I look in the mirror over the years my hair is turning gray, my face has wrinkles, but I am still me.  In fact I am the same me I remember since childhood.  Their is an important clue here.  My brain does not have an IQ rating as high as person X and I can't learn as quickly as I could when I was younger.  But I am still me.  Second important clue.  The body and the mind age but I am still me.  These two clues tell me that the third aspect of my being is more important than the other two. My body and mind grow old and die but my spirit is as fresh as the day it was born. It may go on forever. 

Interactions of the self.

How does the self lose control of itself?  How does the spirit decay?  Their are many aspects of the spirit part of self. Lets examine self control.  I am overweight, I should not eat that jelly role. I eat the jellyrool.  The junky will kill for a fix.  The killer shows no emotion. Assuming that all spirits start of as a blank sheet,  which is a logical conclusion since their was a time when it did not exist, it was conceived then physically born, the other aspect of self, mental and physical can shape the soul. 
 

Interactions between self and community

Nurture.  The self is not alone it is in a family and a community of self's.  Self becomes in the reality of community before it has the opertunity to discover itself.  This is why periods of meditation or isolation (desert experience) can be beneficial.  Personality is a word that describes the perception that you have of others and they have of you.  It is partly a product of the interaction between the two and the initial seed that has germinated into the spirit aspect of self.  It is unique and even identical twins in identical environments do not sprout identical personalities. A "bad" seed can have it's influence felt for many generations as a parent's love and compasion can influence and guide the Spirit down through the great grand child.

The spirit flows from each of us to all who are around us and to those who follow us.  Our spirit is not confined to our bodies it can be carried out the door and to school or work by other members of the family or friends.  It flows through the community interacting with others and returning back to the home with bits of other personalities that it has been influenced by.  It is true that the physical self returns effected by the environment it entered ( Ex: a black eye) and the brain comes back with more knowledge, but it is the self that digests, analyses and incorporates the outing  and uses it  to modify or update the spirit self.

The spirit is the soul of the individual.  Their are good souls and bad, loving and evil, creative and destructive.  How they come about is to complicated to speculate, but it is safe to generalize that compassionate souls nurture compassion and hate filled souls nurture hate.   However: the only soul you have control over is your self.  No matter what the environment or the nurture there will come a point when you will come face to face with your self.  If your spirit is strong it will overcome all mentally, physical and environmental calamities.  In the final analysis you are who you chose to be.

Dealing with troubled souls
 
 

The self mystified by it's existence.

I sit on my balcony with a pot of soil waiting for a seed to be placed in it.  The soil will give form to the plant that will sprout.  The blossoms will soak up the rays of the sun.  It will live.  I have never ceased to be fascinated by being in existence but that day it overtook me with mystic wonderment and joy that lasted for months.  I Exist. I made it. I am alive.  There is nothing in my being that you cannot find in this pot of soil. But I live.  Fifteen billion years the universe has been, and now I am. Life is "wonderful, a miracle, beautiful, magical". It was a eureka moment that I tried to share with others but they thought I was nuts. Sometimes happiness has to be enjoyed within and filtered out slowly in controlled doses.   But god dang it, it is freaking good to have existed.
This homo sapien has made it to the planet earth.  To those of you who have just arrived I welcome you into existence and hope you enjoy your stay.  To those of you who are about to leave I hope you can slide into home plate with a smile on you lips  shouting the words. What a Ride!!!
 
 

The self faces its mortal nature 

http://www.seeklyrics.com/lyrics/Supertramp/The-Logical-Song.html
but please tell me who I am.

How the Spirit dies.
 

If the spirit is strong nothing can hurt it. But this is often not the case.
Your spirit can only die if you let it die.  T

You are talking to your self, discovering who you are.

A hand full of dust.