During our 20's, we chatted a lot about our relationships. We brought our friends and family into the relationship circle with us without nary thought to the importance of privacy. We seemed to need the world to view us as part of something grander than a singleton.
Coupledom is what we sought out and many times we found ourselves disappointed by our significant other or the relationship in general.
It wasn't until our 30's that we learned not to share every detail of our relationship. Maturity was a big reason why but, mostly we are embarrassed by the less than perfect reality of our relationship.
As we move into our 40's and beyond, we stay mum about our relationship because we want to keep things private. Not for the purposes of pretending to be perfect but, as a way to respect what should stay private.