-- no effort whatsoeverYet forty isn't even technically middle-aged anymore. And there are upsides: After a lifetime of being clueless, Druckerman can finally grasp the subtext of conversations, maintain (somewhat) healthy relationships and spot narcissists before they ruin her life.  What are the modern forties? What do we know once we reach them? What makes someone a "grown-up" anyway? And why didn't anyone warn us that we'd get cellulite on our...