There was a man started with the clothes on his back and ended up with diamond mines!…The man knew what he wanted and went out and got it! Walked into a jungle and comes out, the age of 21, and he’s rich! The world is an oyster, but you don’t crack it open on a mattress!
– Arthur Miller
Death of a Salesman, Act 1. Willy is envious of his brother Ben becoming rich by discovering a diamond mine in Africa at the youthful age of 21. Ben is a symbol of the American Dream for Willy. In this conversation with son Happy, Willy uses the metaphor of the world as an oyster to describe how Ben succeeded in cracking it open to find diamonds not by sitting "on a mattress" but through hard work.