Most people do not use the word "attachment" to describe what is happening in their relationships.
They describe the pattern. The same withdrawal at a certain point of closeness. The same fight that arrives in different relationships with different people. The sense that intimacy, when it reaches a certain depth, starts to produce its own particular discomfort. They may know that these patterns connect to something earlier. That knowledge has not changed what happens when they get close to someone.
The early relationships that shaped how a person relates did not communicate through reasoning. They communicated through repetition: what happened when there was need, what happened when there was conflict, whether closeness was reliably safe or carried a particular cost. These became templates, held in the body and the nervous system as much as in the mind.
What persists is not the original relationship. It is what the original relationship taught: the implicit assumptions about how things go, what to reach for, what to pull away from. These run automatically, which is what makes them so difficult to shift through will or insight. A person can know intellectually that the person in front of them is not the person from their history, and still respond to them as though they are.
The template is not a defect. It was built for a specific environment. The problem is that the environment changed and the template did not.
What changes it is not better understanding of where it came from. It is new relational experience that repeatedly fails to confirm the old prediction: a relationship in which the expected withdrawal does not come, in which need does not produce the anticipated response, in which closeness turns out to cost something different from what was learned. This happens slowly, through consistency over time. It does not happen through analysis alone.
The work is not insight into the past. It is new experience in the present, long enough and real enough to update what the system is running on.