There's a sweet sadness, a meloncholy reminiscence that's at the core of this song. The writer is in the process of change, and thinking that things simply won't be the same any more. We do not now the circumstances. After all, this is not a story-song, and one great purpose a song can serve is to apply to many people in many places. So it's talking about change and the emotions around it in metaphors.
There's a sweet sadness, a meloncholy reminiscence that's at the core of this song. The writer is in the process of change, and thinking that things simply won't be the same any more. We do not now the circumstances. After all, this is not a story-song, and one great purpose a song can serve is to apply to many people in many places. So it's talking about change and the emotions around it in metaphors.