I base a lot of my headcanons around the Pocket Monsters: The Animation novels (and I highly recommend reading the translations; they contain some really interesting information!) Anyway, I was rereading them again today to refresh my memory, and two things really stood out to me in terms of Pokeshipping:
Ash explicitly says that the first day of his Pokémon journey is a disaster, but he says this before ultimately meeting Misty. Of course, we all know their first meeting isn’t necessarily the kindest, but I love the idea that in the future, Ash can look back at that day and be like “I thought that was going to be the worst day of my entire life, but then I met the love of my life and now that I think about it, things weren’t so bad after all!”
It’s very interesting just how different Ash and Misty’s school experiences were. Ash went to the small primary school in Pallet Town and was apparently bullied quite a bit, while Misty went to an all girls school and didn’t have very much interaction with boys because of it (save for one specific instance where she “lured” a boy in and beat him up for making fun of her friend…classic Misty honestly.) Not only does that paint an interesting contrast between the two of them (Ash a victim without many friends, Misty a defender with friends) but it actually explains a lot about how they first interacted with one another. Misty tended to be more hostile and quick to assume things with Ash, likely because the very limited experience she had with boys prior to meeting him was negative and involved hurting people she cared about. Ash, on the other hand, had experience being bullied and likely felt that Misty was doing just that, so he was always quick to stand up for himself since there was no Delia or teacher around to do it for him the way they did while he was in school. Obviously they both ease up over time, and I don’t even know if this is something that they themselves would realize, but I can absolutely see that being a major factor early in their friendship.