I always figured trauma would blur and hide your personality. Kind of like having the psyche as housing a network of glass. Sometimes people break that glass in the house and you either fix it, leave it the way it is, or throw it out. This is normal and this is human and environmental interaction and how human beings have the capacity to change certain parts about them as they see fit to survive and thrive.
But trauma is more like a car crashing into the side of the glass house. Too many pieces inside that house become broken and one can't figure out what should be fixed, left alone, or thrown out. The person tries haphazardly to just get the car out of their wall and fix everything just to feel the safety of the home again. But by doing this the new foundation is weak because the first thing in sight is used as a foundation. Because of this some of the strong points of the psyche get isolated and ignored and the integrity of the psyche is weak and faltering.
With a weak foundation, the walls of the house can fall down from a simple pebble being thrown at just the right place; and a person walking through the house can cause walls, ceilings, or large glass structures to topple accidentally just by breaking one little piece of glass in the house. So the person is often rushing to repair walls or ceilings and constantly deciding what should be fixed, left alone, or thrown out. This leads to too much frustration and fear and a desire to want to give up.
But if one doesn't give up then to fix the weak foundation requires help. Either the person has to find a way to protect the house so everything can be taken down and structured around the strong points of their psyche or prioritize which parts can be protected and restructured, one at a time, or someone has to protect the house while it gets steam-rolled and rebuilt.
But the problem is if the person was so vulnerable to begin with then they probably most often don't have help from another to either protect the house while it gets rebuilt or protect the whole house or even parts of the house themselves so they can rebuild it strong.
What most ends up happening is either the person accepts that parts of the house will have to remain vulnerable while the other parts get restructured (the hardest and most fearful option) or they go far inside the house and build a smaller but extremely durable house, riding their lives on the reinforced strength of the few of many strong points of their psyche.
By building a smaller house, their house becomes boring, cramped, and less welcoming out of fear that it will be destroyed like before. Then it becomes a life of staying in the smaller house until death or periodically facing fear and expanding the house to include the other strong points of the psyche, one at a time, but not as strong as the little house, sometimes never fully repairing and including all parts of the original house.