You are not what happened to you

If I am not what happend to me, how can I be what I choose to be without looking back at it as if it happend to me?
I chose my actions which led to what happend to me. Nothing just happens in life, I can have good luck, I can have bad luck, I can have nothing, I can have everything, I can have something.
If I choose what to become, what makes that any different from looking back at it as if it happend to me?
I am what happend to me. How can I be something that I have not yet chosen to do? I can think that I am what I choose to be, but unless I am it, then I am not. And even if I do it, there can be interventions in life that makes something else happen to me. Am I truly what I chose to be then?

/r/Existentialism Thread Link - i.redd.it