Who are we?

Who are we, really? I have reflected on this question from time to time, without answering it.

Let me explain what I mean. Have you ever known someone whose personality changes when getting older and somewhat senile? Let's say a man has been an upstanding family man, and a community & church leader. But in this senility he becomes a "dirty old man". Who is he? Is the real person the person that he was by the exercise of his will? Or is the real person who he became when he could no longer exercise control of his mind?

What about someone who becomes intoxicated on alcohol or drugs? Perhaps she is a mild mannered woman by day, polite and kind to folks. But at night when the alcohol takes over, she becomes abusive and violent. Who is she, really? Is the real person that person she is by day when she is exercising her will? Or is the real person that person she becomes when the inhibitions are removed?

Are we that person we choose to be, or are we that person that comes out when we are controlled by a drug or the enemy of senility? Or are we possibly only who we are at any given moment in time?

We may think of how we Christians are "two people" -- the old man and the new man. I don't discount that. But do not the above situations apply to mankind in general? They are not traits only displayed by Christians, are they, but part of the human condition? I wonder about the answer to these questions, or whether the questions are even valid?