I wrote the above before reading any of the comments, but there are a couple other ideas which people touched on but I did not. I’m bringing them together here, mostly for my own future reference:
Humans have the ability to model the outside world in our own minds, including other people, but not our own minds. Because of this, it seems like our choices aren’t subject to causality. Credit, and more detail, here.
Another comment goes into more detail of why this is. In order to fully model itself, a mind would need more power that it has. Therefore, minds cannot predict their own actions with high fidelity. For minds that don’t intuitively understand concepts like recursion, this implies that their own future actions cannot be predicted, and that therefore free will exists.
If we have separate neural hardware for processing human actions and for inanimate events then this might lead to the idea of free will, and then also several other odd notions.