Recovering from a severed relationship, the author is trying to get used to the idea of being alone. It doesn't quite register. He has invested so much love and so much time in a relationship that he and his lover thought would last eternally, so the notion that it could just end as quickly as it started seems so strange. How could all of those promises and words of devotion not mean anything if they weighed so heavy at the time. "It don't mean much" is not so much a declaration by the author as it is an attempt to grasp the idea that the other party is so ready to call it quits. A similar song to look up would be "I'm Not in Love" by 10cc.
Recovering from a severed relationship, the author is trying to get used to the idea of being alone. It doesn't quite register. He has invested so much love and so much time in a relationship that he and his lover thought would last eternally, so the notion that it could just end as quickly as it started seems so strange. How could all of those promises and words of devotion not mean anything if they weighed so heavy at the time. "It don't mean much" is not so much a declaration by the author as it is an attempt to grasp the idea that the other party is so ready to call it quits. A similar song to look up would be "I'm Not in Love" by 10cc.