Certainly the graveyard scene has its share of unanswered questions. Hamlet is contemplating the skull of the court jester, Yorick (Act 5, Scene 1):
Alas, poor Yorick! I knew him, Horatio: a fellow of infinite jest, of most excellent fancy. He hath borne me on his back a thousand times. And now how abhorred in my imagination it is! My gorge rises at it. Here hung those lips that I have kissed I know not how oft. Where be your gibes now? your gambols? your songs? your flashes of merriment, that were wont to set the table on a roar? Not one now to mock your own grinning? Quite chop-fallen?
In this last act, the act in which Hamlet's fate is sealed, he is thinking of death and facing it squarely as he questions the moldy, dirty, smelly skull. What does it all amount to, really, this thing we call life? What's the point? In the end, we are but things that are of the earth and return to the earth. We fancy ourselves to be something else for a while, but we will be mere objects for a much longer time.