OP topic is interesting. Do I believe in them, Yes based on my own experience. Do I believe the guy in the video? No!
So here is my experience, completely neutral with regards to anything spiritual.
I was 12 & on a week long sailing trip with a school friend and his family. I was asleep below deck in the front berth and had a very vivid in color dream that I was looking out towards the back of the boat & the dingy (normally tied and floating along behind) had come loose. I watched it trail off behind us and disappear.
Don't know if I woke up immediately or some time later. When I came up from below, we were under way and the dingy was gone. I said where is the dingy & my friends parents hadn't noticed it missing till I said something. It was gone....out of sight. Never told them I'd just dreamed it.
At that time in my life I absolutely would not have been receptive to something more substantive. That experience however, made me think of what my Father described after a cardiac arrest when he'd collapsed & died on the sidewalk outside his work in down town Baltimore (I was age 9). Just so happened an EMT and a nurse were walking behind him. He said he watched them work on him, but not from his 1st person perspective, as if he was standing off to the side observing the EMT pound on his chest trying to resuscitate him (broke 2 of his ribs). He again watched them working on him in the ER. He'd lived to tell that & from then on had zero fear of death. He died a year later. My mother later told me, he'd had a premonition that he had 1 week left to live. He'd tried to prepare her. Of coarse she'd have no part of hearing this. He outwardly appeared healthy, but he knew and was correct. I was 10 & pissing mad at God. Then a few years later (age 13 & still pissing mad at God) I went up in the attic to get one of his old suitcases to pack for scout camp that summer. When I opened it, I found inside a letter from my Father addressed to me dated 3 days before his death & fully intended to be read by me after his passing. Also included was a small gift containing a Swiss Army Knife I'd need for camp. His premonition gave him that chance, he'd acted on it, & it meant a lot to me.
Given the date when I started this response 7/8 I'll share one more. Why the delay in posting (you might ask). This shit is personal & I'm pretty hesitant in putting that kind of stuff out.
Date of dream 7/6 2005:
I still remember some of the dream & the only reason I know the date is because what happened 24hrs latter is now history.
I had a very intense dream of a terrorist attack or to be more accurate a plot. I woke in a cold sweat right before it happened. You know how dreams are, somethings in them can be very specific, while other aspects can seam nonsensical. The location was familiar, but it was from a perspective viewing location I'd never been looking at a building I didn't recognize (back corner of a parking lot viewing a building of a 3 letter agency located on Ft Meade). The take away from the dream I couldn't shake was 2 fold. 1st was the impending nature of it i.e. something was going to happen. 2nd was the specificity of the method used. It was an ANFO explosive smuggled in via a cement mixer truck. This dream was so vivid and disturbing I told my wife everything I could remember that morning. Did it happen? Nope, but 24 hrs later 7/7 the Subway bombing in England did. My wife said WTF and was sure it'd been a premonition. There was absolutely nothing in my dream that would have indicated England nor anthing actionable that could have affected what happened, but it does seam to have been a bit of a premonition.
Fast forward 5 months Dec. 2005 (dream long since filed in the memory banks). I had a part time job managing a snow removal plow teams. That year my assigned area of operation was Ft Meade on base. The first snow event I was at the guard shack entrance trying to get the whole team through security. They sniffed our trucks with dogs, opened all the boxes, checked undercarriage with mirrors, and checked our salt spreader hoppers etc. Meanwhile I watched as Cement mixes rolled right through security with no more then an ID check. That dream jumped right out of the memory banks. I walked over to what looked like HMFIC and said hey you know all these mixer trucks rolling through for the construction site, well if you were a terrorist wouldn't that be an ideal delivery method for an ANFO device??? You guys aren't checking them and you should. I have no idea if they implemented any change. I doubt they did, but I did my part.
A year later 2006 for my full time job I was assigned to project manage the exterior glazing package (Blast lvl3) for a Fed gov project. This included live Blast testing with ANFO in TX at Hurricane test labs. I'd not done a Blast project prior. Funny how life works.
Today one of the projects I'm working on just happens to be this.
https://usace.contentdm.oclc.org/digital/collection/p16021coll11/id/4308/
Kind of eerie, and hadn't thought of it till typing this post. It's a building that obviously would have been unfamiliar in 2005 along with other new buildings onsite. Cement trucks still rolling right through! Think I might have another chat with HMIC of security next week.
I think dreams are an odd collective of all things perceived by our conscience combined with some imagination. Maybe when we're asleep our brain is trying to connect the dots of all things our waking conscience/sub conscience perceived. I believe we perceive many things while awake that we are unaware of. Did I glance at the knot holding the dingy to the back of the boat the night before and my sub conscience recalled it in detail while asleep, noting the knot wasn't correct?? Did my sleeping sub conscience perceive that we'd gotten underway?? Did it perceive the ever so slight increase in speed from reduced drag as the dingy released?? Did my knowledge of the OK city bombing combined with current events in 2005 shape that dream?? I had been on base prior so that explains why it was a familiar location? I don't know, but the sub conscience mind certainly has powers we don't understand.
I've had several other dreams like this that held a much more substantive meaning to me & some were spiritual in nature. They've affected several very important decisions in my life, but they are personal and were meant for me, not the Bear pit LOL.
One of my favorite sayings is: "Consequences always bear out the truth"
The consequences of my decisions/actions based on several things revealed to me in dreams have proven them true.
I am an optimistic cynic by nature. No tinfoil hat for me! I like sound logic, reasoning, rational, & common sense. I do have spiritual beliefs, but they are personal, hard won beliefs that have been through the refiners fire. I do think some people have genuine spiritually charged dreams, but I also don't think most have the spiritual discernment to determine there source or meaning.
Do I believe most people that claim to have had a prophetic dream (like OP video), No.
I'd like to know how many times he's watched Constantine? Great movie BTW. and might explain the low flying gargoyles.