It seems to be referring to a relationship that at some point down the line started to fade away, or the couple started to drift apart. Some things can be held onto for a long time, and in some cases it is better to just let things go instead of searching your whole life and probably coming up with no solid answer. Finding "the reason" will satisfy his soul, but letting go all together will satisfy it just as much. Cigarette Daydream is most likely referring to have a smoke and thinking about all of this.
It seems to be referring to a relationship that at some point down the line started to fade away, or the couple started to drift apart. Some things can be held onto for a long time, and in some cases it is better to just let things go instead of searching your whole life and probably coming up with no solid answer. Finding "the reason" will satisfy his soul, but letting go all together will satisfy it just as much. Cigarette Daydream is most likely referring to have a smoke and thinking about all of this.