>>55729592It is partially headcanon since, like I said, some things are kept vague. But there is plenty of evidence to support what I said.
The description of the basic Poké Ball is described as "comfortable" from gen 6 onwards:
>A device for catching wild Pokémon. It's thrown like a ball at a Pokémon, comfortably encapsulating its target.Starting in gen 6, you can check your Pokémon's memories. Gen 8 added some relating to Boxes:
https://bulbapedia.bulbagarden.net/wiki/Memory_(game_mechanic)>[Pokémon] became good friends with the [other Pokémon] in a Box, practiced moves with it, and talked about the day that [Pokémon] would be praised by [Trainer].>[Pokémon] had a great chat about [Trainer] with the [other Pokémon] that it was in a Box with.It's not too much of a stretch to say a Pokémon's ball is like a box, but just for them.
Ash's Pokédex in the first episode of the anime:
>Wild Pokémon tend to be jealous of human-trained Pokémon.The concept of how Wild Pokémon feel and the feelings of Pokémon in general are expanded further in the games.
Such as with Dr. Footstep:
https://bulbapedia.bulbagarden.net/wiki/Dr._Footstep/Quotes>When we travel, I can see wild Pokémon eyeing us enviously...>If my [Pokémon] friends were to see me now, they would be shocked. Or would they be envious of me...?>However, there are some among us that understand human speech...>Some wild Pokémon frown upon others for traveling with humans. They jeer that the caught Pokémon have "forgotten the wild." But that view is mistaken.Those are just a few. There's much more but too many to list here. Wild Pokémon appear to split into two groups, those that seek out humans and those that don't.
N also expands on this divide in B2W2 saying:
>Zekrom and Reshiram are searching for new possibilities by walking alongside humans…>Meanwhile, those that live in the wild try to better themselves without relying on anyone else. 
