Those who know you best can let you down the most, and who knows you better—sometimes most annoyingly so—than your own mom? We each have others who we do consider "best friends. A corollary for thought: Is it possible that moms having children a bit older has led to the phenomenon as well? Williams argues that the mom-daughter BFF phenomenon couldn't have happened without an overall societal and marketing focus on youth—even as older moms are infinitely more common and acceptable, moms don't want to seem old. The friendship, and I'd call it that, if not "best friendship," between my mom and me is one between two grown-ups, even if we do happen to be mom and daughter. Williams posits that the moms who came of age in the sexual revolution, during Vietnam, during the women's rights movement, experienced a norm that diverged from domestic and societal norms.