We spend our lives telling ourselves "This is who I am" while also telling others "This is who you are." But the reality is we do not know who we really are and we cannot accurately say with any certainty who anyone else is either. This is why identifying with Ego and with various labels is inaccurate and arbitrary. This should become much clearer once you've read this webpage.
So let's start with the five dimensions of life. Keep in mind three are physical in nature and two are meta-physical or non-physical.
Physical matter like physical mass is the first, most basic dimension. This is the dimension of your physical body which can be seen as the physical basis for life.
The next dimension can be described as sensation, which takes in emotions, feelings, thoughts, perceptions, which are all based on energy which is more refined than physical matter.
Then there is another dimension of energy and physicality which is based on relativity and relationship. This takes in the various types of 'field' energies which can be perceived by more than one person, such as sound energy, light energy, heat energy, and it also takes in the energy which comes out of such things as love, intelligence, courage, dignity and integrity which is more refined than just thought or 'baser' energies such as fear, anxiety and anger.
Then there is the next dimension which is not physical at all but meta-physical and that is the dimension involving consciousness and space. You cannot perceive space unless you are conscious, nor can you have any physical dimensions of your existence and being without consciousness. All energy and physicality arises out of consciousness.
Then beyond consciousness and space is Akasha, or spirit, or aether, which exists within you and without you. Akasha permeates all the dimensions of life.
Levels of reality and planes of consciousness
Now please keep in mind that all these five dimensions are interactive and interdependent. They are all mutually dependent on one another and go together to define what we describe as living existence. This gives us different levels of reality and different planes of consciousness in which you exist. For example is a tree made of wood, or is it actually wood?
The issue here is that you have two major forms of reality - there is actual reality and conceptual reality, i.e. the reality which arises out of human thinking and human imagination. You cannot say that you have made a tree out of wood in the same way as you can say you have made a table or chair out of wood. Many people confuse these basic forms of reality so they cannot often distinguish what is really real as opposed to what is relatively real. Many things which have reality as a concept do not exist in actual reality. But also many things which are relatively real, i.e. based on a concept or human thinking, are based on actual reality.
So how do you define yourself as an individual human being? Where do you find the 'real' you? You exist on different planes of consciousness.
So where do you decide "This is me."? At what point do you decide that you really know another person? Understanding this will become maybe a bit clearer once you become familiar with Natural Law.