I don't know. What I do know is that songs like "How Do You Keep Love Alive" and "Say Hello Goodbye" never get old to me.
If I think hard enough about it, I would probably have to say that the reason I seem to be so drawn to these songs may be because sad songs are probably the most authentic songs written. Love songs are just so dang marketable. That's why there's a billion of them and many of them seem cheap and fake. You just never hear an A and R guy telling his artist "man there's just not enough pain in these tunes bro". Heartbreak is not flattering. So it seems more likely that someone willing to sing about it may actually be heartbroken. And though I'm not apposed to fiction, I still want to feel like I'm hearing a person and not just what someone feels like they're supposed to say.
Once again, I don't know. I just love' em.