Now that I think about it, this is just anime logic. Sometimes, things never make sense. Eh, but why kill the fun in racking our brains?Technically speaking, this could even be cartoon logic, since there are some qualities of the series that don't follow the guidelines of most animes.
And as we all know, cartoons can make much less sense than animes.
Hold it right there, meme-over-user.What if there is no reason?
Although there are theories everywhere, there actually is a reason why Ash is always 10 years old.
The publisher, I think, of the series has stated that he has kept the protagonist the same age, to keep the main viewing group.
... My new favourite video.
EDIT: OUR QUOTES. THEY KEEP BECOMING SPOILERS.
EDIT: OUR QUOTES. THEY KEEP BECOMING SPOILERS.