Book of the Forest First
Something of a Rocky montage, a wisdom quest. A little like a 'greenwood story' - like the Robin Hood stories in which the heroes live in a place where their identities become negotiable, and without social context people become who they say they are (though really the Vana Parva is more like that). Also a bit like the Clone Wars cartoon - coming between two major parts of the main story, but with a huuuuge amount of time to cover, and room enough for the characters to get up to potentially anything.
I suspect this is also a part of the story where, since the Pandavas have enough time to get anywhere in India. If you have a local temple or a local Mahabharata story anywhere outside the north where most of it happened then this is the period where you can say "Ah yes the Pandavas came here while they were banished to the forest".
Or a bit like Neal Adams Batman Oddesy thing where, here's our main character on the move, in a variety of other situations.
Their main sage tells the Pandavas that, since they are banished for 13 years they should use that time to learn and gain wisdom, the primary method by which they do this is by wandering around, getting into adventures and meeting sages and hearing even more stories from them. All of these tales have some kind of Dharmic point.
None of them seem to inculcate enough wisdom to persuade the Pandavas to not hate Duryohana, its pretty clear they are still going to try to kick his ass when this exile thing is over. Clearly I don't understand Dharma that well...
Arjuna ends up going off to Heaven, or Swarma and encountering Apsaras who teach him to dance, which comes in useful later on. He also gets DIVINE SUPERWEAPONS - which are hidden away.
Then the Book of Virata
the Pandavas have to spend the last year of their exile hidden, so they take up low-status disguises and go to work in the court of Lord Virata.
This is pretty much like every 'Fair Unknown' story from the Arthurian mythos, where a suspiciously clean servant arrives one day and does menial work for a while then turns out to be a Prince. Shared into-European story-structure or parallel story evolution?
This is where Arjunas dancing skills and Apsara experience comes in handy, as he acts the part of a eunuch dance instructor - taking on a female, or quasi-female role. He's actually much nicer like this, its pleasant to see him not being a tit, maybe all that forest stuff did wear off on him.
Their cover is blown towards the end of this period by a sketchy aristocrat lusting after Draupadi, Bhuima takes that guy out. This leads Duryohana to suspect them and he launches an attack on that kingdom, (the sketchy aristocrat was the kingdoms main defender). The Pandavas go to help him, still in nominal disguise, but are clearly super duper guys so give themselves away.
Duryohana says this breaks their promise as it hasn't been 13 years by the solar calendar. They say no we were calculating by the Lunar calendar....
I think my main question from all of this is did they really learn much from all this stuff?
Considered as ordinary people - they went from a state of conflict, learned about Dharma and humility, and then went straight back into conflict. But apparently these are divine beings, or semi divine, and what they do, the whole of it, is a lesson or a ritual for humanity, acting out the divine order.
So this returning to conflict thing is part of that
Also quite possibly this is a beowulf-style situation with a story coming from a slightly older more 'honour-culture' culture, being written down and interpreted in the terms of a more settled 'dignity-culture' culture, so all this barbaric vengeance-based stuff actually has hidden meanings and layers of interpretation.
We will see....