Multiplicity of the mind
If you are like me, and most of the people that I have met, then you most likely believe that you are one person, with one personality. You have a name, a mind, a personality, emotions and a body, and that is essentially who you are.
In most cultures, it is seen as unhealthy to have multiple personalities. Perhaps knowing what to expect from each other supports a sense of stability and safety. We judge one another using comments such as "she's like two different people", "He's schizo", "You're acting like a child".
For most of my life, I remember trying really hard to be the same person everywhere I went, and in every situation. I was afraid to let parts of me be seen that would lead to me being judged as being other than how I wanted to be perceived. This takes a lot of effort to sustain and yet I have come to see that this way of thinking was not helpful. And in fact, it is quite exhausting.