It seems that the "forgetful heart" involved here is the narrator's own heart. He’s lost friends and lovers, but still enjoyed their memories in his heart; now he’s losing that too.
The final line is one of the best in the album. It reminds me (at least in structure) of this line by William Faulkner: “The past isn't dead. It isn't even past.” The meaning there is almost the opposite. The narrator here seems to be losing the past. Faulkner felt we could never escape the past.
It seems that the "forgetful heart" involved here is the narrator's own heart. He’s lost friends and lovers, but still enjoyed their memories in his heart; now he’s losing that too.
The final line is one of the best in the album. It reminds me (at least in structure) of this line by William Faulkner: “The past isn't dead. It isn't even past.” The meaning there is almost the opposite. The narrator here seems to be losing the past. Faulkner felt we could never escape the past.