the world is someone's oyster

From the version of the play The Merry Wives of Windsor published in the First Folio (1623) of the works of the English playwright William Shakespeare (baptized 1564; died 1616):[1] see the quotation. The original context was that Ancient Pistol would use force to obtain a loan from Sir John Falstaff, like prising open an oyster with a sword to obtain a pearl.[2]

• (Received Pronunciation) IPA^(key): /ðə ˈwɜːld‿ɪz ˌsʌmwʌnz ˈɔɪstə/
• (General American) IPA^(key): /ðə ˈwɜɹld‿ɪz ˌsʌmwʌnz ˈɔɪstəɹ/

• Audio (GA)

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• Rhymes: -ɔɪstə(ɹ)

the world is someone's oyster

1. All opportunities are open to someone; the world is theirs.
   • c. 1597 (date written), William Shakespeare,  […] [T]he Merrie Wiues of Windsor. […] (First Quarto), London: […] T[homas] C[reede] for Arthur Ihonson, […], published 1602, →OCLC, [Act II, scene ii], signature C2, verso:

     Fal[staff]. I vvill not lend thee a penny. / Piſt[ol]. VVhy then the vvorld's mine Oyſter, vvhich I, vvith ſvvord vvill open.

   • 1858, Anthony Trollope, “Dr. Thorne”, in Doctor Thorne. […], volume I, London: Chapman & Hall, […], →OCLC, page 58:

     But his wants were not at first great; and though his ambition was perhaps high, it was not of an impatient nature. The world was his oyster; but, circumstanced as he was, he knew it was not for him to open it with his lancet all at once.

   • 1865, Thomas Carlyle, “Peace of Hubertsburg”, in History of Friedrich II. of Prussia, Called Frederick the Great, volume VI, London: Chapman and Hall, […], →OCLC, book XX, page 328:

     Irregular gentlemen, to whom the world's their oyster,—said oyster does suddenly snap-to on them, by a chance.

   • 2008, Nick Clayton, “Introduction”, in The Guardian Guide to Working Abroad, London: A[dam] & C[harles] Black Publishers, →ISBN, page 15:

     The world may be your oyster, but that doesn't mean you've found the pearl.

As the quotations show, the proverb is frequently used with different forms of the word be, and with different pronouns.

• the world is one's lobster

• carpe diem
• seize the day
• take the bull by the horns

• “the world is your oyster, phrase”, in Collins English Dictionary; from Collins COBUILD Advanced Dictionary, 6th edition, Boston, Mass.: Heinle Cengage Learning; Glasgow: HarperCollins Publishers, 2009, →ISBN.
• “the world is someone’s oyster, idiom”, in Merriam-Webster Online Dictionary, Springfield, Mass.: Merriam-Webster, 1996–present.