Who are you?
You may have more say over this than you think.
Perhaps you are simply an amalgation of what you choose-- your thoughts, your actions and your feelings. What you put into the world. You are not a monolith. Maybe you are made out of sand: tiny tiny choices, over and over, until you take form.
The key is to not get mesmerized into believing that you are a finished product, though. Each grain of sand is a choice. And we all choose, again and again and again, that grain of sand.
Choose on purpose. Become who you are, on purpose.