Macbeth is the one who utters this words after "discovering" that Duncan has bene murdered. In this quote, we learn that Macbeth acts shocked to hear of this death. He tells us that everything good in the world is over now because of the death. However, the reader knows that Duncan's death is in fact a consequence of Macbeth's actions.
I would want a rewind button to go back and fix every mistake so my family can stop hating me and I can actually make them feel proud of me instead of them always being mad at me