For me perhaps, the problem lies in "absolutes". I definitley agree that your experiences will affect the kind of choices that you make, but you are able to make choices at odds with your experience.
One experience may tell you that something's a bad idea, while another tells you that it isn't. For example I am lazy, and experience tells me that if I don't do my homework I'll get in trouble. However, experience also tells me that I don't suffer as much from the school's punishments as I do from spending hours doing homework. If you factor in all experiences it turns out that there's always a
reason why people do everything.
It's also related to this:
Damn, this is a tough one. And what about "indecisiveness"? Not being able to make a choice? How does your notion of determinism fit in their? If our choices are determined, why are they sometimes so difficult to make?
If the choices are either both so good or so bad that there isn't a significant difference between them then your experience tell you that they're both equal, so you find it difficult to make the decision. But that's not to say the decision you eventually make won't be determined like the others, it will because you'll still eventually pick the one that seems to look best at the moment you choose.
Fist: Yes, I'd say that all those things could have an effect in determining everything else you do, but equally they might not, it could be something else. But nothing you do is random, there's always a reason, even if you don't know what it is when you do it.