Life's but a walking shadow, a poor player
That struts and frets his hour upon the stage
And then is heard no more. It is a tale
Told by an idiot, full of sound and fury,
Macbeth knows his end is near at this point. The change in tone and the pathos (feeling of pity and sadness) this whole soliloquy evokes gives the impression that Macbeth has suddenly awakened from his stupor. His wife is dead, his kingdom is falling apart, and he is truly alone. All his ambition and sacrifice has been for nothing