LADY CHILTERN. You can forget. Men easily forget. And I forgive. That is how women help the world. I see that now. (4.248)
As a modern reader, it's hard to get around the sexist message of the play's end. One other way of looking at it is this: formerly protective of Sir Robert's impermeable public persona, Lady Chiltern sounds like she'll redirect that energy into caring for the man himself, in all his humanity. So part of her transformation is abandoning idol-worship for the difficult, day-to-day work of accepting and loving a real person. And this interpretation is a little more palatable for someone reading An Ideal Husband today.