While following Pokemon, have you ever wondered why Ash Ketchum has never aged? Why he's constantly telling us that he's 10 years old, despite things like a yearly Pokemon tournament and celebrating birthdays? What's that all about?
As Ash and friends make their way through their journey to be the very best (like no one ever was!), they see many sunsets and some character redesigns that definitely convey the passing of time. But mystery still shrouds Ash's seeming immortality, as he repeatedly describes himself as a 10-year-old boy. Why doesn't Ash age in Pokemon?
Luckily, fans of the show have come up with some pretty rad Ash age theories to help shed light on why Ash Ketchum never grows old.
A pretty heartwarming fan theory as to why Ash Ketchum is eternally 10 is the Ho-Oh theory of eternal happiness. When Ash started his journey, he saw a Ho-Oh, and, as a Pokedex entry on the legendary bird Pokemon states, its feathers grant eternal happiness. Ash's idea of eternal happiness? To be forever on his quest to catch them all.
A few people have the idea that Ash being stuck as a 10-year-old is due to some interference from the legendary Pokemon, Celebi. In the fourth Pokemon movie, Pokemon 4Ever, we see that Celebi is capable of transporting people through time, who appear as different ages in different timelines. This makes sense when you think about how often Pokemon like to totally screw with people.
Remember when Mewtwo petrified Ash into stone in Pokemon: The First Movie: Mewtwo Strikes Back? Yeah, that one scene where it wasn't just the Pokemon crying? One fan theory makes sense of Ash's state of being stuck as a 10-year-old boy by explaining that when he got caught up in that whole mess, he actually died, essentially freezing him in time for the entirety of the series. This ties together the relation of him being frozen by Mewtwo and being literally frozen in time from that point on.
In a rather dark Creepypasta fan theory, Ash's Pokemon adventures are the result of him falling into a coma. His bike accident landed him in the hospital, where he remains in comatose state and the episodes that the audience sees are actually his dreams. These dreams are journeys through his own mental barriers, which he must come to terms with before waking up from his coma, or else he will suffer extreme brain damage. This theory explains the socialist, comforting world (even though it's full of scary pocket monsters), and explains that the characters surrounding Ash are all manifestations of his own inner psyche.