It's only been in the last couple weeks that the lyric, "Why would you say I was the last one?" suddenly made sense to me. It's asking why he would have ever said she (the narrator) would be his final partner/his one great love when there would always be more and he would never be satisfied with just one woman. It seems so obvious and straightforward now, but for whatever reason that line had always puzzled me before.
dust my feathers with his ashes