In the fifth act of the first act, after listening to the request of Ghost's revenge, Hamlet said in advance that he would consciously become crazy and pretend to look for opportunities to kill Claudius. Therefore, it is difficult to conclude that he was mentally ill by misdirected after the oath. Hamlet's so-called insanity became his main method of interacting with other characters in most plays, and it was also the main equipment used by Shakespeare to develop his role. However, problems remain. Does Hamlet pretend to be mad, just merely.
Hamlet is crazy because he acknowledges that he has not been angry many times, but he is irrational in the presence of some people, and he has actions that pretend much I will. Everything that Hamlet did has a purpose. His goal is to do his utmost to revenge his father's death and to conquer his goals. Hamlet knows his performance throughout the game and has complete control over himself and his behavior. His behavior proves that he is just angry because he is not angry, but because someone's uncle murders his father and marries his mother.
This part clearly shows his crazy behavior. People rarely act in such casual and special ways; Hamlet's "crazy craftsmanship" (III.iv.190). Essentially, Hamlet successfully convinced various roles to believe that he was absorbed in the death of his father and intended to reach love with Gertrude. Hamlet continues pretending to be crazy about eliminating Claudius and getting more love from Gertrude. After the death of the King, Gertrude married Claudius immediately after marrying in "worst speed" (I.ii.153, 156) "within 1 month". After a potential security and subconscious competition against Hamlet's father another man advanced in his position. Therefore, Hamlet announced dissatisfaction with Claudius in numerous cases. He insists that they are "alerted to marrying in the form of incest" (I.ii.157). Hamlet clearly showed his aversion to his mother's new marriage. In addition, the ghost explained his death to Hamlet.