The character of Hamlet expresses his inner grief in this passage in a way that reiterates the sense of doom and foreboding from the first scene, prepares the viewer for what is to come, and shapes the character of Hamlet so we can better understand his actions later in the play. Hamlet is a play in which a son has to avenge his father, and from the beginning of the play it is clear that the loss of the father has been a devastating blow to this young man. In the passage under discussion (I.ii.76-86), Hamlet is answering his mother as to why he is so unhappy and why he cannot put aside his grief for his father as she tells him he should. The passage presages much of what is to come, offers some of the underlying motivation for Hamlet's subsequent actions, and demonstrates from the first that there is something wrong in the kingdom and that it has something to do with the king's death.
The first scene has set the mood for the play, and this second scene carries forth ideas and images created in that first scene. The fate of kings is tied to the order of the universe, and dissension and tension in one is reflected in the other. In Hamlet the disorder in the kingdom derives from the fact that the natural order has been challenged--a king has been murdered by his wife and brother, and Hamlet is to act to restore the natural order by avenging his father. The appearance of the Ghost at the beginning of the play shows the degree to which the natural order has been sundered. Hamlet will later be told what to do by the ghost of his father, whom he meets on the ramparts at night. In this passage, Hamlet angrily denies that his show of grief is only appearance, and the images he evokes are the expected external images of grief--black clothing, woeful breathing, crying, and an unhappy expression. He evokes these surface indications of grief to show that his own grief is not mere show and is much deeper than these outward expressions...