To start, the suggestion that dreams only reflect the processing of our waking world is technically an unprovable hypothesis, as no one but ourselves have direct access to our interior experiences. Reports are needed to validate this hypothesis, and reports are always subjective by nature...a scientific “no, no.”
The subjectivity of dreams does not mean, however, that direct subjective experience is not valid or worthy of examination. As another comment mentions, dreams have a long history of being considered prophetic and meaningful throughout history. Unfortunately, the sceptic in us discounts all first hand accounts of dream experience as being merely subjective—as if dreams could ever be anything else. A whole category of human experience is therefore reduced to scientific platitude and second hand judgment because of “lack of objective evidence.” In other words, dream states are resistant to scientific objective study, and therefore are subjected to academic hypothesis and theory—the creation of a “story” that processing is all that is happening. First hand evidence is therefore generally dismissed, despite being more grounded in reality than the theories that supplant first hand reports.
From personal, first hand experience (gasp), I can attest to dreams being prophetic. I have had a number of specific dreams that seemed to be significant...so much so that I immediately told my wife on awakening so that she would be able confirm things if they turned out to be prophetic, as I suspected.
One dream foretold the hit and run death of my four year old neighbour (backed over in a driveway...a very specific way for a four year old to die) and another foretold a workplace fire at a relative’s place of employment, which happened two days after I related the dream. Again, a very specific event that was conveyed in a somewhat symbolic, yet direct, dream.
The details, of course, are everything in these matters and the source of the “report” (myself in this case) is inevitably deemed by science to lack credibility because all reports are subjective. Nice catch 22 there—a facile dismissal of human reality and truth based on the “lack of experience” of the critic, as much as on the non-objective nature of a report.
Until you have direct, personal experience with dreams being more than just processing of ”reality” (which they definitely do do, by the way...just not exclusively so), then you are likely to reject a reality which is simply out of your own personal experience. Cheers.