Amazing question It is a fact that not matter how hard you try to be YOURSELF in the first stages of your life (childhood/adolescence) many traits of your personality are created by the influence of your parents,friends and others. (society overall) Your environment.
*Not the mention the twisted minds that are created due to abuse and negligence of parents.
Not even the most mature kids have the ability to filter what is coming to them.You do something so much that becomes a habit and it becomes YOU.At some point it becomes a burden and starts to bother that's when I believe existencial crises happens.
Natal chart is a blueprint.(Stagnation)
Synastry is a combination of charts of two people who are in constant movement.Or who can be in movement at any minute.
I wonder:
Do you think the natal chart is "who you are" = who you became due to the environment. Or the natal is who you are in essence.Your heart?
If is not YOU 100% probably someday you will comeback to who you are or close to that but your chart ain't gonna change with you.
I believe the natal from a child who grew up with no stress and freedom of expression is:
70% essence
30% product of environment
People who grow up through abuse and pain.Controlling parents.Emotional blackmail and so on...The list is giant..
Most likely 30% essence
70% product of environment
People change.Usually through pain.For the better or worse.