the world is someone's oyster UK /ðə ˈwɜːld‿ɪz ˌsʌmwʌnz ˈɔɪstə/US /ðə ˈwɜɹld‿ɪz ˌsʌmwʌnz ˈɔɪstəɹ/ saying1 •All opportunities are open to someone; the world is theirs.Fal[staff]. I vvill not lend thee a penny. / Pist[ol]. VVhy then the vvorld's mine Oyster, vvhich I, vvith svvord vvill open. — 1597