The United States is on the verge of using military force against Syria's dictator Bashar Al Assad because of his alleged use of poison gas, and that although poison gas is definitely a weapon of mass destruction, the term "weapon of mass destruction" is never used?
In the US (and England, I'd wager), "To be or not to be" is the most quoted line from Hamlet. It's hard to take a discussion or conversation anywhere with "Alas! poor Yorick, I knew him."
"To be or not to be" asks Sartre's question a few hundred years in advance: "Why not commit suicide?"
Can I change my statement from "utterance of it's most famous phrase" to "most iconic scene"?
As for Sartre's question, it would be absurd not to.