What constitutes your identity over time? That is, what makes it that you are the person who, for example, graduated from high school or had that specific 5th birthday that you had?
What constitutes our identity over time can be very hard to say. What we have left of our memories at old age or almost any age can be different from the truthfulness of a memory or situation. What constitutes, in my opinion, is what residual truths we have about ourselves or about the world, that have been stored in our minds, regardless of our conscious knowledge of them.
From our own perception of self, the ideas and concepts that we pick up are used as driving factors in our own conception of who we are. The specific perception of our lifetimes in our memories is dependent on the physical functioning of our brain, yielding a rather large amount of qualification in order for our interpretations of the world to remain existent at all.
If there is anything that is able to be denoted as our “self”, this would appear to be it. When we die, it is the perception of death that scares us, but also the idea that we are no longer going to have agency in this world. It is the fear that all of our own unique thoughts, ideas, and actions are going to die along with our physical selves. There are certain practices that are built on these assumptions such as the Jungian idea of “active imagination”. This derives from the notion that because we are independent beings with our own individual presets of interpolation and processing, anything that follows (including our own imaginations) are purely an output of a system that we are not totally aware of having. What sticks in our minds as we learn and grow in life, is just as important as what does not, and the practice of analyzing our creative imaginations seeks to further our understanding of these forces. This practice serves to highlight the less thought-about fragments of our being, bringing to light what we have not yet discovered about our true identities.
To summarize, both what we are and are not aware of, in our own characters, are equally important to who we are and who others understand us to be. It seems that the more we think about who we are, the more that we realize our own lack of control over it. While we think that we are capable beings in control of each and every one of our own actions, we are not, and this is much more often true than we would like to accept. It is only with an understanding and appreciation for what we cannot control about ourselves, that we are able to truly gaze into our own souls and take what we find as true.