This in itself is not an act of insanity, as the guards and Horatio also observed the apparition. Soon after this encounter, Hamlet informs his friends Marcellus and Horatio that he is going to act insane to avenge his father. Horatio warns Hamlet “What if it tempts you toward the flood my lord, or to the dreadful summit of the cliff That beetles o’er his base into/ the sea, And there assume some other/ horrible form which might deprive your/ sovereignty of reason, and draw you into, madness? Think of it” (1.4.69-74). This warning may have been what gave Hamlet the idea to fake insanity, as it is immediately after this encounter that Hamlet begins to act insane. Hamlet only claims madness because it allowed him to get away with prohibited actions, and disables others from taking him seriously so that he can carefully plot his revenge free of suspicion. Hamlet tells Horatio and Marcellus about his feigned insanity, and tells them to think nothing of it. Hamlet does not inform Claudius, Gertrude, Ophelia, Polonius, Rosencrantz or Guildenstern of this plan to ensure they do not interfere with his plan to kill Claudius. However, Hamlet does later inform Gertrude about this plan and states that he is not mad, but “mad in craft” (3.4.192). He is disrespectful, uses several sexual innuendos and makes bold sexual remarks to Ophelia such as “That’s a fair thought to lie…