Cats as a class, have never completely got over the snootiness caused by that fact that in Ancient Egypt they were worshipped as gods.

Wodehouse’s joke rests on a familiar bit of cultural lore—cats’ association with divinity in ancient Egypt—and uses it to explain, mock-seriously, the modern cat’s air of superiority. By treating “cats as a class” like a social set with collective memory and lingering entitlement, he satirizes both feline aloofness and human tendencies to rationalize animal behavior in anthropomorphic terms. The humor comes from the mismatch between grand historical worship and everyday domestic cats, as if millennia-old reverence has produced permanent “snootiness.” It’s a compact example of Wodehouse’s light, epigrammatic wit: an elegant, pseudo-scholarly explanation offered for a commonplace observation.