In Act 1, Scene 2. Claudius is trying to lift Hamlet out of his depression. He thinks the depression is caused by the death of Hamlet's father. So, he says to Hamlet that Hamlet's father lost his father, and his father lost his father, etc. Thus, death of a father is a natural thing and Hamlet ought to snap out of it. Then he says, "think of us[Claudius] as your father. This is probably one of the worst condolences Claudius could choose. What he doesn't realize is that one of the reasons Hamlet is so depressed is that such a short time has passed since his father's death and his mother has just married his uncle. During Elizabethan times, when the play was written, this act would have been considered incest---not to mention tasteless and unthinking. But Claudius is so wrapped up in his new power, that he can't imagine why Hamlet would be upset.