the ocean is (someone's) oyster

Translations
весь мир (кому-то) открыт
Now that he has graduated, the ocean is his oyster.
Теперь, когда он окончил университет, весь мир для него открыт.
Definitions
This phrase means that someone has many opportunities available to them, or that they are in a situation where they can achieve anything they want. It suggests that the world is full of possibilities for that person, much like finding a pearl in an oyster.