It is usually the worst cop-out a writer could pull on an audience but think about it: Star Trek V is All Just a Dream. Specifically, it's one of Captain Kirk's dreams. As such, it reveals a lot about his inner psyche:
Kirk is, as pointed out on the YMMV page, a Canon Sue. Wouldn't Captain Kirk like to think of himself this way and dream of himself in this way?
Spock and Sybok: is there a deep-seated pyschological fear of someone, even a (gasp) strange relative that Kirk has never even met coming and taking Spock away from him?
With the ease at which Sybok "converts" the Enterprise crew members, is Kirk worried about someone taking them away? Or does he have a deep-seated fear of loss of control ("I'm LOSING COMMAND!")
Uhura dancing naked: Kirk Fantasy #546. 'Nuff said.
And pretty much everyone else's too. Did adolescents in the 60s really watch TOS to see Kirk or were they looking over his right shoulder?
Scotty is shown as pretty bumbling in this movie. Could it be that Captain Jimbo doesn't have an entirely positive view of his Chief Engineer?
For that matter, does he not have entirely positive feelings for the Enterprise? It is shown as being constantly breaking down in this movie. Or is it just the "new" Enterprise? Maybe Kirk is pitching an unconscious hissy fit: "Starfleet gives me a replacement Enterprise, but it's not myEnterprise! I want my old Enterprise back!"
"I miss my old chair."
The Crack Pairing of Scotty and Uhura: again, is Kirk afraid the Uhura might not devote all her attention to him, or does this show that he is just a closet shipper?
The Klingons destroying a poor, helpless, little Pioneer 10 spaceprobe (complete with pathetic scream!) deep in Federation space! Those bastards! They killed my son!
On that note, of course they want to track me down and engage me in battle ("if I could defeat Kirk..." "...you'd be the greatest warrior in the galaxy!")! I'm James ***ing Kirk the Magnificent! ...Okay, killing Kirk may have been a dream of a lot of Klingons at this point, but remember from Star Trek IV that Kirk is more infamous than revered by Klingons at this time. The "Kirk is a great legendary warrior" thing doesn't seem to stick until well after he's dead... or at least Star Trek VI.
More than once, Spock talks about whether life is a dream, as he deals with the image in the bookending song "row, row, row your boat".
"The Planet of Galactic Peace" is a lawless wasteland, with the posted ambassadors nothing more than misfits that nobody else wants to deal with. His belief that the three powers can't ever find peace?
Or, alternately, he's just telling this as a camp-fire story to Spock and McCoy (note how they are sitting around the fire at both the beginning and end of the movie) who probably, because of all of the examples above call him out on his crappy story telling and tell him to just shut up already so they can drunkenly sing "Row, row, row your boat."
Spock's uncharacteristic faith in Eden shown in the TOS episode "The Way to Eden" is because he secretly believed in what his brother was searching for.
Why would Starfleet send a starship that's literally falling apart, undercrewed, and generally unready for service to solve the Nimbus III crisis? They weren't sending the Enterprise. It was basically just a taxi for sending James Kirk, the guy who talked his way out of omnipotent aliens, tied multiple computers into knots in 15 minutes or less of conversation, and has hosted multiple contentious political conferences and delegations. The cult on Nimbus III is about 30 guys armed with sticks and pellet guns, and Starfleet could take care of them in minutes if they approached it as a military problem. They were sending in a hostage negotiator, and just didn't expect him to cut straight to pretending he was playing Rainbow Six. They also had no idea Klaa would get in on the action, either.
A possible reason for the numerous problems the almost mint-condition Enterprise-A is having in this movie? It was in Spacedock during the Probe's sojourn to Earth.
Alternatively, Roddenberry suggested it's problems were because it was actually the Yorktown, having been renamed and rushed back into service after the loss of the Enterprise, hence why it comes across as a second-hand ship.
If Scotty knows the ship "like the back of his hand", why does he end up smacking his head on an overhanging bulkhead? Because he was likely thinking of the Enterprise, not the Enterprise-A. Furthermore, it's likely that not all Constitution-class vessels were refit in exactly the same way, particularly if this ship was originally the Yorktown.
It's never outright stated, but it's a safe bet that Kirk's greatest pain is the death of his son.
In what is very likely a combination of both Fridge Brilliance and Fridge Horror, there is a lot more going on during the row, row, row your boat scenes than at first appears. First off, depending on how you look at it, this is either three best friends on vacation shooting the shit over a few beers, or three very lonely work colleagues with few other real friends, no real social life and no family who have no choice but to vacation together. This ties in with the general theme of aging and loss that is running through films 2 through 7 with regards to Kirk and Picard; where you can go on all of these wonderful and exciting adventures, visit incredible planets and meet exotic aliens never before seen by any human, but when the journey is done, you will be coming home to an empty house because the rest of your life has passed you by. Secondly, Bones's anger towards Kirk recklessly endangering his life on the mountain is very likely foreshadowing the revelation of his secret pain later on in the film where he was forced to turn off the life support for someone that he cares deeply about.
It makes perfect sense Klaa would be snooping around Sol (which is why he shot the Voyager probe). He's trying to get some action and getting into a petty fight with a Federation ship would be just so cool to him. It also explains how he knows there's an emergency - he got the news of Nimbus III from the Federation broadcast, not Klingon.
Vulcan infants can remember the moment of their births - is it possible Spock can remember (albeit subconsciously) incidents that happened in utero?
When members of the Enterprise crew sneak into the bar in Paradise City, the Caitian table dancer attacks them. During the struggle, the Caitian is knocked unconscious and thrown into a pool of water. She would probably drown (being unconscious) for doing nothing more than defending her place of employment from nighttime intruders. It's a cruel move by the "good guys", but the movie treats the innocent victim as expendable.
Obviously, for whatever reason, once it's flushed and resealed the waste is vented right into space. Which, when in spacedock, would mean probably splattering some poor maintenance worker's windshield.
The same reason you can't use train toilets in the station. Anywhere else on the Enterprise they probably just use the transporter...