I spent awhile lurking on a forum where one of my ex-es posts just to see if he said anything about me. Finally it sunk in how unhealthy it was for me to do that. If he had said something positive, I'd have gotten all maudlin about how it didn't work out. If he'd said something nasty, I'd have gotten all worked up over that. If he'd said nothing at all (which actually seemed to be the case), I'd be going, "WTF, five years, and it's like I never existed!"
LOL, once it's over, there's really nothing good that can come of unneccessary contact of any kind. Yeah, it might be a bit of a self-esteem issue going on, here. Part of us always wants them to get up one day, realize what FOOLS they have been for letting such a good thing get away, and vow to punish themselves to the end of their days.