You're the one who still doesn't get it, and I've explained why and how to solve that. From my original post, I foresaw that we would not be able to convince each other (argue for eons.. and never agree), which is why I offered an alternative.
Following your logic, you would be correct, but your logic has flaws such as:
"If ideas are determined by chemistry, then it does not matter..."
Your perception of what matters is not absolute or tangible, it is merely a construct in your head that can dynamically change.
"If ideas are determined by biology, then you are determinist and i am undeterminist not because these ideas are correct and fact-based, but because our respective molecules lead us to think that way..."
The molecules inside us aren't the only variables affecting what our brain collectively believes in. The primary agitator of the brains beliefs are the external environment (our life history, the things we've seen, read, etc.). Furthermore, internal molecules by themselves, without external stimuli, would be like having a human since birth being in a sensory deprivation chamber. Not much would happen in such a persons brain.
The primary difference between me and a mechanical clock is that I have senses, like other animals, which allows me to adapt to an ever-changing environment. The clock, is basically set until it wears out or something tremendous happens to it, it doesn't have much of an advanced way to observe and react to the infinitely changing environment around it (it does, just not enough to be very impressive, for example, vibrations and other forces are effecting the way it mechanically moves but it's basically imperceptible to us). So, you compared two completely different things which have almost no similarity. It was a bad example and the point is mistaken. Humans are predetermined to have certain things, like hands, feet, a brain, etc. by DNA. These collectively form a body which, if all goes right, has the ability to monitor and react to a very complex environment, in this way, we are never really finished like a clock is, we continually unfold for the entirety of our lives. While this is all determined at some primary level, it is beyond our ability to tell everything which will happen next.
To put this into simple terms for you, yes.. we are definitely going to react to this discussion in a way that couldn't have been any other way. However, you also know that a rollercoaster has a fixed path and destination, yet people still find purpose in going to ride rollercoasters. This misconception you have that just because something is fixed then it must somehow be tainted, and already known about, is completely flawed. If you've never seen/ridden the rollercoaster before (never lived out your life completely, as no one alive has) then you don't know everything that comes next. You can know that whatever comes next was always going to come next, but you can't know exactly what it is. You can however know, for example, that if the past 10000 miles of a very long rollercoaster have obeyed certain rules of physics, like never going into a randomly appearing wormhole and changing direction suddenly, then it's probably not going to happen next. So while you don't absolutely know what is and isnt going to happen next, you can kind of have a good idea by using your senses and past experience to reason. In the same way, you can use your senses to reason that the multitude of humans that were wrong in the past about us being the center of the universe, and the first creatures created on Earth (oops, dinosaurs), and the sun revolving around us, and witches being real and casting spells and need to be hanged (oops), etc., you can use this "historical roadmap of past lives" to determine, with all but absolute certainty, that magic, superstitious fairytales, and similar concepts given without cause-effect or stimulus-response deductive reasons, are nothing more than what they seem - superstitious in every way.
Another problem you seem to have is that "if everything in reality turns out to be fixed, then because I previously thought it wasn't fixed, then nothing can change." The reality here is that things are always changing, the path they take is fixed but mostly unknowable, and it will be determined by the "atoms or molecules" in front of you, which have to be placed there in the first place, like this post, for it to all unfold. Essentially, this reduces you to being like the rest of the animals, just a bit more clever. It is deeply humbling to a free-will believer, just as it was deeply humbling to people who thought they were the center of the universe, but being humbled or humiliated isn't the end of pleasure, curiosity, or purpose in our lives.