No one wants to know you're happy.
Seriously. They don't. They say they do, they feign interest in the oh-so-cute-and-romantic stories you share, but at the end of the day, your misery is more entertaining and your happiness less so.
Your migraines are more entertaining than your happy marriage.
And your minor car accident is more interesting than your brand new car will ever be.
So when things are going well, we may find ourselves keeping to ourselves more than we should. We make the effort by not discussing "that" topic, because... well... the happy stuff is boring.
A good story is moving, captivating, involves trial and error, misstep and misfortune.
And a happy ending is much easier to take, if it's preceded by a tumultuous plot.
As a result, we sometimes delve into the past too much, chatting with people we promised to ignore because they make things interesting. We retell painful moments from years ago because we've "come out of it unscathed" but all the while our reminiscing reopens a wound we'd hoped to have healed.
The storyteller in us wants some substance, something full of emotion, something bad that we can make good with words and hate mongering. We seek something to hold their attention, because our happiness only causes an uneasiness that our more painful moments never seem to.
But with each retold story, of heartbreak or sadness, we not only bring our audience down to a place where they can feel something, but ourselves as well.
Poisoning our present happy moments with reminders of the sad ones.
Giving up our contentment for camaraderie instead.