Even today, over half a century later, she remains one of just 15 people to earn an “EGOT” by winning all four major entertainment awards: Emmy, Grammy, Oscar, and Tony. By the 1960s, she was averaging more than one new film per year and, by everyone’s estimation, she was on a trajectory to be a movie star for decades to come.But then something funny happened: she stopped acting.

Source: When the 80/20 Rule Fails: The Downside of Being Effective