Do you get to choose who you are for today? What mask will you choose to wear? Benevolent and helpful person? Horrible malevolent *******?
Or do you even have a choice? Are you are static and unchanging?
Who is it that chooses who you'll be today, tomorrow, or in your life?
Who are you? Is it the person others perceive? That you perceive? Or are you something beyond that perception?
I tend to fall in line with this reasoning:
"A disciple of the noble ones considers this: 'I am not the only one who is owner of my actions, heir to my actions, born of my actions, related through my actions, and have my actions as my arbitrator; who — whatever I do, for good or for evil, to that will I fall heir."
Upajjhatthana Sutta: Subjects for Contemplation
My actions change, I change. The problem is trying to align who I am with what I do. Kind of like trying to make sense of the reflection in the mirror.
It's a bit frustrating when I'm prematurely defined by what I do. What I say is like training wheels. If people throw aside what I say and just focus on what I do, they're only getting what I'm working on; that, changes all the time. I guess I keep people on their toes by just being me. Other times friends and family see me in one way only that to "be" someone else would bring up objections and reasons why I can't be someone else-lack of resources, illness, limitations, so have you.
I don't know who I am if going by what I value and believe. I just realize who I am by what I continue to do. The former is in reflection of the latter not the other way around. Like the Dharma mentions, everything is in constant change. So, who would be a verb of action rather than a noun like a soul or spirit.