@autumnramc,
It may be the case that, since we can trace causes and events in the past with hindsight, we make an assumption about the future resembling the past in that way. But perhaps we only trace some events when our attention is focused on them, or that we select those in particular
because they are traceable.
Of course, our understanding of past events in which we participated and by which we assume the future is predictable in the same way, assumes that we
correctly identify the causes and effects of these occurrences. What if our account is at best only---plausible?
We want to know, even if we can look backward and see that events were "determined" why the future operates in the same way. Are we perhaps, moreover, mislead by a crude conception of scientific law that makes cause and effect iron-clad in its results instead of a guess that is very highly probable? "The sun will rise tomorrow" is not absolutely guaranteed. And can scientific law about the operation of physical bodies be extended to the world of human occupations and preoccuptations?
We make plans, devise strategies, develop simple or highly complex projects. These are based on our knowledge of how the world works, but at the same time, don't we always "hedge our bets" with conditions about dependencies of one thing upon the other.
We plan to meet a friend at a certain place and time. "I'll see you there" we promise. Now of course, we can break our promise in a spiteful manner, or decide to do something else entirely at that time. Yet, isn't it always that promisses about performing simple actions in the future usually contain some provisions? "Unless it snows," "unless I get pneumonia","unless I am called in to work. And these are considered "legitimate excuses" by both parties because they understand that plans are subject to outside forces beyond one's control. Where does predetermination fit in here?