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I don't think that's what @kyriacos implied, perhaps more that we can't claim sole authorship, to do so would ignore the influence of every external factor and actor that we cannot exist without, be it starting conditions, inspiration, intervention, culture, etc et al.

These reflections parallel Kundera vs Nietzsche fairly well; is all pre-ordained or unique, is there any free will? Unlike the arguments, I don't think the answer is so polar. I don't think there is an answer, at least not in the context of the question as most ask it.

Believe what you will, do no harm, ease suffering if you're able, make life interesting if only for your own distraction. Or don't.

It's all stardust in the end, until the heat death of the universe. But that's a way off yet, and long after the failing of all human endeavors, after all the stars have gone dark, and entropy has won over information.

Or will it?

Do we even know the full extent of the verse? If it has a beginning and end what is beyond those bounds, how long/far does the end extend?

I realize the position that every individual has a number of influences upon their actions and thoughts, perhaps we can't claim sole authorship, yet it will be claimed anyway.
Do we claim authorship of the cartoon that a child used to watch, upon penning a book deal detailing how the individual became successful, if the cartoon instilled goals that the individual achieved? There is a problem with authorship vs ownership here also and how they differ.

I think a compatibilist view is most close to the truth, it all depends on how you define free will and what degree you accept your every action is determined.

It isn't possible to ever know the full extent or infinity (or greater than infinity if not only measuring numbers).