Because any experience, whether pleasurable or not, leaves its memory trace as a certain impression of oneself, a certain impression of the other person or object, and an affect between the two, Kernberg’s triad of the self-representation, the object-representation and the affect become the building blocks of the infant’s psychic structure. So as the infant grows and receives impressions, many units of such triads form, these being units of object relations. In time, the various object representations fuse to make an overall object-image, and the various self-representations also fuse to make a total and cohesive self-image. This happens in the fourth and last stage of the separation-individuation process.

Strong and/or repeated impressions tend to become fixed in the soul, becoming part of the overall ego restructuring. These impressions can be positive or negative, pleasurable or painful. Some of the most well known and problematic one's are those due to painful or intensely conflictual experiences of early life. These include abandonment and loss, hatred and judgment, severe intrusion and lack of empathy, and so on. A specific subset of these is abuse. When the child is subjected to abuse of any kind, the pain and conflict around events and situations are so powerful that the impressions are quite lasting. We can see this in the many individuals who were victims of emotional, physical, or sexual abuse, the effects of which can not only last a lifetime, but tend to structure their experience in painful and difficult ways.

Self-boundaries determine even what one is able to think. While it is true that different impressions stimulate different thoughts in the same person, still these thoughts are pretty much determined by the person’s sense of who he is, that is, his self-image. So the thoughts that go through a person’s mind are not really accidental, chaotic, or disconnected, although they may sometimes appear so. They appear chaotic because a large segment of the self-image is unconscious or preconscious, and thus shapes thoughts and experiences in a way that the conscious mind cannot be aware of. This fact makes it possible for a person, by careful observation of the patterns and trends in his thoughts, to gain much information concerning his sense of identity. We usually think of a positive or negative self-image. Indeed, some boundaries can be seen as “good,” as healthy or useful; others are more obviously limiting or false. But they remain boundaries, whether we call them good or bad. Some boundaries allow more freedom than others, but every individual has specific boundaries which limit his particular experience and action.