] I really wonder if it was caused by the thought of Hamlet murdering someone ~ anyone. Her beloved Hamlet first goes insane and then commits murder; the thought's overwhelming and she can't handle it.

You're right - it's not just her father's death that gets to her, it's that the man she loves could be responsible for it.

] Still, it's hard for me to swallow. I realize that a lot of things happen in Shakespeare's stories that wouldn't happen in real life, but Ophelia's insanity has to be at the top of my list of things that don't seem right.

I agree - it seems like a rather extreme reaction, but I think that in those days people thought that women were more mentally unbalanced than men, anyway, so Ophelia going insane when Hamlet didn't might make more "sense" to them!