King Hamlet was beyond annoyed that Hamlet did what every child does when his parents ask him to do something, and he did exactly the opposite. Not only had Hamlet told his mother about his poor choices, but he had yet to kill Claudius. In Hamlet's defense he had a good reason why he hadn't killed his uncle yet (definitely a great conversation to have over the holidays) and half of Shakespeare's characters had taken the time to make sure things were done right, then they probably wouldn't it would have happened. It won't be a real tragedy. Hamlet had waited to kill Claudius because he was not sure whether the ghost was his father and therefore did not want to commit an unnecessary sin. However, he still failed because he entertained the ghost of King Hamlet and that is a shame in and of itself. In order for Hamlet to decide whether or not he can trust his father's ghost, he decides to put on a play based on his father's murder for his mother and uncle. While the play was taking place, Hamlet kept an eye on Claudius and all his emotions and that is how Hamlet knew that the ghost was not an evil spirit, but was definitely his beloved father. Once Hamlet comes to terms with the fact that he is failing his father even after he is dead, Hamlet is able to come up with a plan to kill Claudius so that he can suffer in the same way that he did.