Hamlet often appears to be “mad” in the play. The question is whether he is doing it on purpose or doing to keep the queen and king guessing about his intentions and state of mind. At one point in the play, he appears to push Ophelia away, telling her that he does not love her, regardless of how she might have interpreted his intentions.
About all we really have to go on is Hamlet’s reaction to her death. When he sees Ophelia’s brother, Laertes, jump in Ophelia’s grave, he leaps in and begins to struggle with him. Hamlet says:
I loved Ophelia. Forty thousand brothers could not with all their quantity of love make up my sum.
In other words, Hamlet says that he loved Ophelia much more than her brother could have. Is it true? I’m not sure that we can be certain one way or the other.