Pokémon remains one of the most beloved franchises of all time. Be it the numerous games, various manga, or beloved anime series, Pokémon remains a cultural landmark. However, almost as major as Pokémon is its beloved mascot, Pikachu. Most fans remember Pikachu as the electric mouse Ash Ketchum is forced to accept from Professor Oak in the anime, who, eventually, ends up becoming Ash's closest companion. Even as Ash dumps his other companions after every season (Misty, Brock, May, Dawn...), Pikachu remains as Ash's greatest friend.
However, a new theory on the FanTheories subreddit argues that Professor Oak didn't just arbitrarily give Ash his Pikachu. He needed to give this particular Pikachu to Ash or else the cosmology of the Pokémon universe would have crumbled. And it all has to do with a certain twist in a certain Pokémon movie.
Sammy and Samuel
In the fourth Pokémon anime film, Pokémon 4Ever - Celebi: The Voice of the Forest (also known as Celebi: a Timeless Encounter) introduces the legendary Pokémon, Celebi. Celebi is a unique Pokémon whose abilities allow it to travel through time -- sometimes taking other things with it across existence.
It just so happens that in Pokémon 4Ever it encounters a boy named Sammy, who defends it from a Pokémon hunter. Celebi, in its attempts to escape the hunter, travels through time, taking Sammy with him to the modern-day, where his path crosses with Ash, Misty, Brock, and Pikachu as they travel through Johto. An adventure ensues.
During the course of the film, Sammy grows close to Ash and Pikachu, taking even to sketching an image of Pikachu in his notebook. At the end of the film, Sammy is sent back in time to his original state.
However, it turns out that Sammy is, in actuality, a younger version of Professor Samuel Oak, the same Professor Oak who started Ash off on his journey.
The theory acknowledges a few core facts established by this film. Professor Oak knew that Ash would have a Pikachu, but none of the other starters. Ash, in the movie, uses his Pikachu and Bayleef in front of Sam. From Oak's perspective, he knew that Ash needed to form a close bond with his Pikachu, or else the timeline would be ruined.
Once he realized that Ash came from Pallet Town and would be coming to him to start his Pokémon journey, he knew he had to give Ash a Pikachu. If he didn't, he would create a time paradox, which could lead to unknowable damage to the fabric of reality. So ensuring Ash gained a Pikachu was vital.
Does It Hold Up?
The theory seems very concrete upon first glance. Professor Oak did play a key role in introducing Ash and Pikachu at the start of the series. And Pokémon 4Ever confirms he knew Ash would own a Pikachu forty years before Ash set off to be a trainer. However, does the theory hold up under scrutiny?
The big assumption here is if Professor Oak realized that Ash's starter Pokémon was a Pikachu. At no point does Ash confirm that Pikachu was his first Pokémon to Sammy. Therefore, it isn't possible to say he knew for sure if he didn't give Ash his Pikachu that the greater timeline would collapse.
Furthermore, Ash only received a Pikachu from Professor Oak because he failed to arrive on time. Gary and two other trainers got their starter Pokémon before Ash, leaving him with only one Pokémon left. It is possible that Professor Oak expected Ash to arrive late, but that would imply that Professor Oak convinced Ash's mom not to wake him up on time after Ash accidentally broke his own alarm in the middle of the night. That's far too much calculation.
4Ever Already Creates Time Paradoxes
Besides, Pokémon 4Ever already creates a couple of major timeline paradoxes on its own.
Consider this: Sammy learns from Ash about the Pokédex. Years later, Professor Oak gives Ash the same Pokédex he shows to Sammy. Oak, along with a Professor Westwood of the Seafoam Islands, ends up inventing and writing the entries in the original Pokédex. This means that Ash told Sammy about the Pokédex that he'd end up creating.
The timeline paradoxes here boggle the mind. Yet the Pokémon universe remains the same.
In this sense, the theory doesn't hold up. However, a variant might.
It Means So Much to Him
While Professor Oak might not have felt the weight of the Pokémon world on his shoulders when making sure Ash left his lab with Pikachu, there might be another motivation. Perhaps Oak didn't plan for Ash to take Pikachu from him but left the option open because he knew Ash would form a lifelong bond with a Pikachu.
Consider how in the first episode Pikachu's Pokéball is marked with a unique insignia. It's kept separate from the other starters so no one else can take it. This indicates that he always intended on giving Pikachu away. Professor Oak might have kept a Pikachu safe for Ash not because he thought he had to give him a Pikachu, but rather because he felt he should give him a Pikachu. He knew that, by giving Ash this Pikachu, he'd form a lifelong companion through the best and worst of times.
It is clear Ash remained a fixture in Professor Oak's mind. He kept a forty-year-old notebook on him that included a sketch of Ash's Pikachu, suggesting he remembered his adventures through time quite fondly. So he had to be aware, on some level, that giving Ash a Pikachu aligned in the cosmic timeline in its own way.
In this sense, Sam isn't some Time Lord correcting time so it flows as it should. He's just a man who wants to leave the world a better place than he left it.