I should add something which I think helps illustrate my viewpoint...
I talked about the pre-existing soul ("the beginning you") as if it is an object cut-off from the rest of what follows, but this is not exactly what I mean. The pre-existing soul is not cut-off from what follows, but rather, the pre-state, current state, and final state make up one whole object. This holistic view of an individual existence means that you can't fully compartmentalize free will.
What I meant by saying that "we have a choice to make 'the beginning you' anything we wish" is that, holistically speaking, you can't separate our free will agency from what we are as individuals. That is, you can't go out and think and do all sorts of good things and not have those good thoughts and good actions be unrelated to what you are as an individual. Likewise, you can't go out and think and do all sorts of evil things, and not have those evil thoughts and evil actions define you as an individual. Your thoughts and actions define you as an individually since they are holistically linked to who you are (i.e., your identity). Similarly, "the final you" is interwovenly related to your thoughts and actions.
Hence, this holistic pespective of 'self' and free will, I think, helps to shed some light on how it is possible for an individual to be held accountable for their actions even though - in the wider perspective of things - there really is no such thing as 'free will' (i.e., a will that is free to be whatever it wants to be, even free to be something different than what it really is). We have no such freedom to be something different than what we really are. We are what we are, and that can't be changed. The free will agency imbued to us (I think) is that we choose what we are, and if we are wise, we will choose rightly. If we choose righteousness, then we are made righteous, hence we were predestined from the beginning. If we choose unrighteousness, then we are made unrighteous, hence we were predestined as unrighteousness from the beginning. Fortunately, no one is in a position to be compelled to choose unrighteousness since in the smallest of matters they can freely choose to be righteous if they want to be. This is how, I believe, it is possible for free will to exist.