Talking Meowth and Ash's old Pokemon

Every time this comes up, I'm confused. Did they ever explain why Meowth is the only Meowth who can talk? Even other characters that met Meowth were surprised it can talk. Professor Sycamore was like, "Oh wow, a talking Meowth."


Did they ever explain this? I've watched all the episodes and I don't recall them ever explaining why Meowth can talk.


Also, in the XY series, when they went to summer camp, why doesn't Ash acknowledge he used to have a Bulbasar, Charizard/Charmander, and Squirtle himself? Is XY a continuation series? I assume he left those Pokemon with Professor Oak when he traveled to a new region.



I found it weird that he never acknowledges the memories he had with his old set of pokemon...or whatever happened to Jessie and James' Koffing and Ekins in the new series. They just showed up with a Wobbuffet.


Maybe I missed a few episodes.