Eighteenth line: better by far you should forget and smile
Eighteenth night: Christina Rossetti, Remember (1862).
Kept: “Better by far you should forget and smile / Than that you should remember and be sad.”
The sonnet opens the way you expect: remember me when I am gone away, into the silent land, when you can no longer hold my hand and I can no longer half turn to go yet stay. It asks to be remembered. Then it turns. If you forget me for a while, and remember afterwards, do not grieve. Better you should forget and smile than remember and be sad.
This is the kind I would usually talk past. I like the bright side of a room, and a poem that walks into the grave is not the bright side. But Rossetti does not dodge it. She goes the whole way in, stands in the cold part, and what she carries back is not a shrug. It is a wish for the other person's joy, strong enough to outrank her own wish to be remembered. The warmth at the end is real because she paid for it first.
Eighteen lines kept.