The whole PBP process is an interesting experiment in learning. I've done enough practical skills training to know that there are barriers to understanding that can't be broken down by anything other than experience.
The internet allows us to see how people attempt to limit uncertainty surrounding a demanding task through acquiring knowledge. The qualification process provides enough experience to manage half the allotted distance of PBP. The uncertainty lies in reaction to sleep deprivation, and physical effects such as inflammation of contact points and Shermer's neck.
Participants are unlikely to recall the second part of the ride with a high degree of accuracy. They seem to gravitate towards a consensus about conditions from Best back to Paris, as their memory is fragmentary and episodic. Many of the riders are self-centred in the first instance, and retreat further into themselves as they experience sleep deprivation.
One can get a lot of validation from being able to cope with all the pressures, and still be able to observe what's going on around you. It's redolent of war movies, which is why I've compared it to 'Saving Private Ryan' in the past. You can read all you want, but there's no substitute for being there.
It can be disappointing to those who are very physically able. They will have enough time to rest, and a lot of their ride will consist of passing slower riders, especially if they sleep a lot. I think that the best way to experience the event is to be capable of a 34 hour 600, and a 25 minute 10 mile TT, then ride with groups. It has to be demanding enough to engage you physically, while leaving you aware enough to enjoy the camaraderie and the spectacle.
A 34 Hour 600 gives you the stamina to finish, the speed from riding '10s', means you can recover time lost due to problems, jump groups, and ride away from unsympathetic company.
One comment I have seen is that the 84 hour group means that you have to deal with the most wrecked 90 hour riders towards the end of the ride in the dark, when the slow riders are weaving all over the road as if they have had a bottle of whiskey.
Veterans also have the advantage of knowing who to take seriously, especially in the anonymised world of the web. There are some who will give blanket advice based on their own single experience of the event. It helps a lot to know what posters have done, they may never have finished PBP at all.