trust no one quotes
Don't chase someone who won't chase after you. Don't give to someone who doesn't appreciate you. Don't love someone whose not going to love you. And NEVER push a loyal person to the point they no longer care. It takes work to get a person to that point and once there ... It's hard to repair the damage
A quote I think fits Ophelia's view on Hamlet very well. Hamlet changes from what Ophelia believed to be a man who loved her into someone who has lost his mind who she must no longer love. He claims their relationship was a lie, and then tells Ophelia to "get thee to a nunnery" and "trust no man", letting her know she should stop believing in him, even if it hurts.