No unanswered question in all Shakespeare beats that one. And before you point to Hamlet, he actually resolves to be or not to be, though in a sneaky and backhanded way three acts after the question’s first posed. (“If it be not to come, it will be now. If it be not now, yet it will come—the readiness is all. Since no man knows aught of what he leaves, what is ’t to leave betimes? Let be.” Hamlet V, ii, 168-170) We know whether that’s a dagger Macbeth sees before his hand. (It’s not, though that opens a dialogue about the reality of images and fantasy beyond the scope of this parenthetical.) We know what Rosalind and Celia think of falling in love. (They’re for it.) We know that if they prick us we do bleed, and if they wrong us we do revenge.
But this question haunts the canon: What the fuck, Iago?