But What About Free Will?
This is where things get a bit technical. See, on one hand, our future is already determined. On the other hand, not only we feel perfectly capable of choice. Truth is, it is actually impossible for us to avoid it -- simply because refusing to choose is also a choice!
So what's going on? How could both statements above be true? Well, perhaps it all boils down to the limits of our knowledge. See, in order to realize the only predetermined future, we must make certain choices -- and, no, knowing what those should be is not impossible! At least not in theory. In practice, however, it would take a quantum computer bigger than the Universe itself -- which is impossible, and theoretically so.*
This in turn means that we can't know for sure which of all possible futures will materialize as the predetermined one. We can't always know what to choose -- and so, we must keep winging it instead. This, therefore, is free will -- "free" only as much as it is unconstrained by the exact knowledge.
If you stop and think of it, this is one major difference between knowledge and intuition -- knowledge restricts our choices, while intuition liberates our creativity. And we need both. We need to know, as much as we can, lest we become hopelessly confused, lost in the infinitude of possibilities. But we also need the courage to trust our intuition when dealing with uncertainty -- to overcome, that is, the inherently limited nature of our knowledge.
* In fact, simply having that big-ass computer won't do because now we would need an even bigger computer to simulate the first one, and so on and so forth into infinity. Which, again, a hard no.