If free will was not real

[GrandizerII]

So I ask you why you like this flavour of ice-cream and you say it's because you always have done.
And I ask since when and you say since you first tasted that flavour.
And I say why did you first taste that flavour and you say because it was available at a certain time.
Eventually you will forget how it all started but if you had a perfectly recorded history it would go back to your birth and further.
Everything and anything. Like dominos, everything is a link to another link.
If not, then what is driving us? We are just an extension of the big bang (if the big bang is real) and we have 0 free will.
We are no different to rocks. What made that rock decide to erode over time?
It didn't decide and neither do we, but thinking we decide is part of that process due to our complexity.
I haven't heard an argument against this yet. To do so would be to provide an 'outside of the universe force' that makes you decide things outside of the links.
The conversation we are having is not pre-destined because it happened at the time it happened, but if you could reverse time a year from now it would be exactly the same and if not, why not?
That is the evidence that is needed to prove free will exists.

We do decide, though, unlike a rock. Activities occur in our brains that eventually lead to the formation of decisions. Of course, that's if we're going be the standard definition of "decide" and not some definition I'm unfamiliar with.