Have you ever thought that people around you resisted you changing?
Maybe they resist you having a change in attitudes or ideas, even ideas or attitudes about your self. Maybe people have resisted you taking a different role in a relationship.
I've found this to be a phenomenon I've noticed in my life and the lives of others.
Others changing can cause discomfort and in turn can make others question who they are.
This seems to be related to the concept of Identity Negotiation.
The above linked Wikipedia page says about Identity Negotiation:
Identity refers to the processes through which people reach agreements regarding "who is who" in their relationships. Once these agreements are reached, people are expected to remain faithful to the identities they have agreed to assume. The process of identity negotiation thus establishes what people can expect of one another. Identity negotiation thus provides the interpersonal "glue" that holds relationships together.
This is about identity within the context of relationships, which I'd guess plays a role in people's personal (non-relationship) identities.
I think it's very often that in relationships, people like to know what they can expect from the other person/people, and maybe without these expectations, relationships and the identities of the individuals in them can be compromised.
The same Wikipedia article goes into the conflict resolution perspective of identity negotiation from a psychological perspective:
When the expectancies of perceivers clash with the self-views of targets, a "battle of wills" may occur (Swann & Ely, 1984). Such "battles" can range from short-lived, mild disagreements that are quickly and easily solved to highly pitched confrontations that are combative and contentious. On such occasions, the identity negotiation process represents the means through which these conflicting tendencies are reconciled.
Maybe you've seen the "battle of wills" that can occur when a person does something, or adopts a different identity, and the other person opposes it.
Overall, I think we need to allow people the freedom to adopt identities that are not regulated by the others around them. I think if we look very carefully, there is a tendency of people to keep others "exactly how they are", and exactly how they want them to be.