So, is Hamlet really insane? I would have to say so.

When Gertrude asks Hamlet why he "seems" to be taking the death of his father so personally, he responds that no outward behavior on his part (wearing an "inky cloak," sighing, shedding tears, and so on) can "show" what he truly feels inside. If the "trappings" of grief are like a theatrical performance, as Hamlet suggests here, then performance is ultimately ineffective – an actor could never truly capture the kind of anguish Hamlet feels inside. Of course, this inevitably draws our attention to the fact that Hamlet's lines are being spoken by a stage actor, which makes the entire passage seem self-conscious. Just how powerful is performance? Is it possibly for an actor to reproduce a feeling like grief in a realistic way?

Is Hamlet Insane or not Insane? | Yahoo Answers

Is Hamlet insane? by Molly Broom on Prezi

Hamlet Essay | Is Hamlet Insane? | GradeSaver