It's your genetics, combined with previous experiences possibly starting at conception, combined with current environment, that causes your thoughts, I'm pretty sure.
If you're that sure, you should tell us about the genes, conception and current environment that made you think so.
You reading my words just now
caused you to have
some sort of thought.

That's how I think this goes. lol
But it doesn't. And even if it made me think, it wouldn't make me think anything specific. I have the ability to think it through, decide to wait and ponder upon your words etc. I can also decide to say to myself, 'Well, **** her. She is stuck in her behavioristic ideas and probably won't be able to see beyond them, so why bother?'
That is one of the many things that constitute free will: We can contemplate, revise our first perception of something, respond or not respond, forget the whole thing because we become preoccupied with something else that we find more interesting, etc. Nothing's determined.
I really don't see room for actual free will.
Your free will obviously allows you to think so. It also allows you to change your mind.
I think it's just a powerful illusion.
Then you should change your words to: I hallucinate that it's just a powerful illusion.
I guess I kind of subscribe to the computational theory of mind.
https://en.wikipedia.org/wiki/Computational_theory_of_mind
Even computers can run different kinds of very diverse software. And nowadays they have the ability to learn, too. But they still don't have free will - which is actually a pleonasm: If it's not free, it can't really be a will.
I have a really hippy-dippy way of looking at it, though, that's fun as at least a thought experiment. Here's how it goes:
My consciousness is a akin to a song, my brain is the instrument, and the universe itself is the musician. Other thinking and feeling entities (you, other people, my dogs, the cat, etc) are also songs, and we "riff" off each other, sometimes in beautiful ways, and sometimes in "musically" horrible ways.
Anyway, just my take on it all.
Interesting: So your carefully thought out analogy to the universe is somebody who is
willing his inanimate instrument to play a certain tune ... or not.
In discussions like this, also in this forum, I often answer with a question:
"What makes you think so?"
And it never fails! Never once did anybody say, 'Well, you know, I was delivered with forceps, my mother breastfed me till I was nine, and I dropped out of college after one year. I guess that must be it!'
Instead, even hard-core prederminists always come up with their actual
reasons for thinking whatever they're thinking.