>>103210825Because Pluto used to be and the definition of Planet changed for largely political reasons because we detected a bunch of Pluto sized objects and decided bigger text books were dumb so we lowered it to 8 and added a byline instead of teaching people about smaller planets and where they form.
Jerry was taught it was a planet and the actual context for the definition change didn't circulate that far. So just like in real life he reacts badly to rules changing without his consent.
