I don't think people ever actually change. I think that we just discover who we've been the whole time. Often times people say, "You haven't changed" when they see someone for the first time in a long while. Looking back at home videos, I think to myself, I've always been sarcastic and witty.
There was one scene that struck this idea in me. The video is of me at two years old, and I am dancing in the living room. I have a tea mug filled with water on the coffee table. It is summer time. My brother walked in as I sipped my water. He joked, "that's my tea!" and I shook my head to say, "no, it's water!" He laughed and said, "that's my water!" I realized that my two-year-old self was not egotistic. I understood that just because I knew there was water in the mug, my brother did not, and I corrected him. I did not just stare at him and wonder, "what are you talking about?"
This moment made me think that I have always had the same mindset, the same wit, the same personality, I just realize who I am the older I get. Maybe that is why some people seem more mature than others because they discover who they are faster and have that confidence.
I think we all have the same principals from when we are young as adults. Our principles just become more advanced as our vocabulary and experiences expand. As a child, if you were shy, you will probably continue to be shy as an adult. Some of us are better in certain areas than others. Some of us were born artists, athletes, signers, bakers, chefs, nurses. Anyone can learn the anatomy of a human, but no one can learn how to be compassionate. The best nurses are not the ones who aced the test, but those who can put their learning to practice and have the natural ability to be compassionate and decisive. Compassion, love, selflessness, these are all innate characteristics. I believe that as we grow, we simply realize the characteristics we've had all along.
I'm no scientist, but to me, our personality only shines brighter as we grow. So, the question remains: are we becoming who we are or discovering who we've always been?