Scholars postulate that the only thing that does not change is the every varying world. Other renowned thinkers postulate that the natural state of all things is to remain the same. Perhaps both propositions are vital. Perhaps it is normal to resist change because it threatens our present state of being. Perhaps it is natural to attempt to preserve the status quo because we are part of the external world and we wish to persevere, not expire. Perhaps it is inevitable that we all change. The natural forces are impossible to blunt.
A personality alters itself through a series of self-referential experiences. We are not the same as the day before. Much as a person can never set foot in exactly the same river on any given day, we are different each day. Yesterday made us, but the past cannot contain nor restrain us. We can never mentally scroll backward and be who we used to be. We must move forward in the stream of life until the day that our life force dries up and we return to dust.