But I can't say that the physical processes in me are in any fundamental way different, than physical processes anywhere else in nature. Most are deterministic, some may be inscrutable, and some may even be random or unknowable - but all those things can be said about the weather, too. You cannot derive my wants from my capabilities (unless you're prepared you ascribe wants to clouds as well, I guess).
But you're again missing the point. It feels to me like I have choices. I believe you're right, I have choices. You're kicking down an open door when you're arguing this.
What I'm telling you is that I didn't come to this belief empirically. And indeed I believe it is impossible to justify empirically.
My point is that this comparison doesn't make sense. A cloud rains because it's undergoing a physical process. You drink because you decided to drink (and only then, inside your body, the water is undergoing a physical process). It's usually hard to decide not to drink, but still - there's a huge categorical difference in what's happening in either case.