I finished a Dickens story just last night that this poem reminds me of, The Haunted Man. This guy made a deal with a phantom to erase all of his troubles and sorrows from his memory. Once done, he became a man filled with anger and hate, trying to drown in waters too shallow, unable to touch any heart except with anger and hate. He managed to recognize his state, and to seek a woman who knew only love, despite many troubles and sorrows in her past. We learn that it is because of the sorrows that a man can love at all.
I wonder if it is a fine line as to how much is too much to bear. Is there a diminishing return on gathering sorrow? I feel there must be.
If we dwell too much on the losses, and not enough on the joys that came before them, we can become quite sour pussed. This character had succumbed to that. When he volunteered to lose the memories of the sorrows, he lost the memories of the joys as well, and turned from simple grief to unintentional evil.