We are who we are

As the hours passed by, one after another, I felt a great pleasure knowing all the things I had achieved over this relatively short period of time. My mind wandered off, thinking of what makes us who we are. There is an incredible struggle between who we are, who we want to be, and who others perceive us to be. The answer is not a consistent one.
Despite knowing this, I would go back to the basic question of who I perceive myself to be. I couldn't come to a clear conclusion. I don't know who I am and this troubles me. Am I to consider myself unpredictable in the long term, or does this simply not matter? What I choose to do, for whatever reason (selfish or not) will ultimately define who I am.