what makes us "us"?

I believe we are always changing, or can be as I would assume there are people moving through life such a state of patterns and routines that they do not experience anything new to challenge or change their perceptions.

Lock said of Bodies (substances) that two substances cannot occupy the same time and place, and one substance cannot occupy two places at one time. He gives examples of a horse, once young, it could grow to be fat or thin. The horse in either of these two stages is still the same horse, though very different. Physically the horse has changed much, but I would also gather that due to those experiences of either over abundance of food and lack or exercise, or lack of food and or over exertion, would have tremendous impact on the horses personality as well.

I do not have the same views as I held as a child, or even as a young adult. I would consider myself as a drastic example of someone who has in a sense become a very different person through the course of my life. All of my life experiences, social, personal, etc helped to form my perception of the world, and how I chose to move through it. Then at 18 went through a series of events that caused me to… that allowed me the opportunity to really look at those views and beliefs, and realize that they were just my experience. Though they were real to me at the time, and they composed my reality, I do not consider them to be actual reality. I truly believe that we create reality as we go along. Now im not saying that we can fly at will or anything like that against the natural laws, but our perception and interpretation of life is what creates our reality. And though it can be real for us at the time, I believe that it must be some kind of second reality, or lesser reality, because at the same time two people can have completely different experiences and outcomes from the same event(true reality). Two employees can be laid off at the same time, and for one it could be devastating and traumatic, leading him to drinking and depression, perhaps the loss of property etc. For the second person it could be taken as an incredible opportunity to explore true happiness and other dreams. Can I argue that the same actual reality, the loss of the job, is the true reality, and the outcomes are the individual experience each one has from these events?