In scene 5, macbeth speaks some of the most famous lines in shakespeare: "out, out brief candle! / life’s but a walking shadow, a poor player / that struts his hour upon the stage / and then is heard no more. it is a tale / told by an idiot, full of sound and fury, / signifying nothing." what does this quote mean and what does it reveal about macbeth’s feelings about life and death? explain.