My favorite writer is Stephen King. I suspect he gets a lot of inspiration from his enviroment. He writes a lot about his hometown of Maine and seems to get most of storylines from the silent town he resides in. Hope this helps!
The correct answer is that he has lost his mind.
Ophelia thinks that Hamlet has finally gone completely mad after saying those words to her. She is confused because one day, he would be totally normal, and the other, he would be saying such phrases to her that hurt her. She wishes he would be normal again and that they could be happy, but unfortunately, that doesn't happen as she kills herself, and he is murdered in the end.