Oh, wow—a movie with a Shakespeare quote for a title. What a novel concept.
Recognize the quote in question? No? We'll give you a hint: it's from Hamlet.
Check it out:
For who would bear the whips and scorns of time,
Th' oppressor's wrong, the proud man's contumely,
The pangs of despised love, the law's delay,
The insolence of office, and the spurns
That patient merit of th' unworthy takes,
When he himself might his quietus make
With a bare bodkin? Who would fardels bear,
To grunt and sweat under a weary life,
But that the dread of something after death,
The undiscovered country from whose bourn
No traveler returns, puzzles the will
And makes us rather bear those ills we have
Than fly to others that we know not of?
This is a passage from Hamlet's famous "to be, or not to be" soliloquy, which centers on the concept of death. Heavy. In this passage, Hamlet uses the phrase "the undiscovered country" to refer to the afterlife, our lack of knowledge about it, and our fear of it.
The movie twists this meaning, using the idea of the undiscovered country instead to illustrate the unknowability of the future, especially in times of historical significance like the one depicted in the film. However, both usages of the phrase have a one thing in common: that they illustrate our terror in the face of the unknown.
Plus, Shakespeare quotes are just inherently epic. We don't know if you've ever heard of him, but that guy was good.