in a world of one's own

(figuratively) end of the world

(idiomatic) the ends of the earth (an extremely remote place) / (idiomatic) the maximum possible / (idiomatic) an insurmountable challenge or obstacle

(Platonic philosophy) world of ideas, world of forms (higher ideal world of which tangible reality is only a shadow image)

completely alone, all alone in the world

(simile) older than dirt, old as the hills, old as time

feminine singular of vieux comme le monde

feminine plural of vieux comme le monde

all the tea in China

(Louisiana, Cajun) a foreigner