Well the deaf girl can hear now, so it is clear that sometimes people do have control over natural conditions.
either we have control over our fate and can change it, or if me manage to fix the problems we run into we were determined to do so. the end result is the same. we can't tell the difference because we don't know what our fate is. as a result it is pointless to even try to tell a difference. because any attempt to say that we are not determined to solve a problem is defeatist. how can we know which problems we are determined to solve and which not? the only way we can find out is by trying. if we fail, then maybe we are not determined to solve that problem. but we'll never know, therefore we must not give up trying. and in this case we solved the problem, so we obviously were determined to do so, hence no delusion here.
you are deluding yourself if you believe that you can tell your determination. being able to do so would imply that you can see into the future.
because i can't tell the future, i can't tell what i am determined to, hence the whole point becomes moot.