A few months before Sandberg told women to "Lean In" in her popular book, Facebook's chief operating officer included strong messages about gender equality in leadership positions in her 2012 commencement address to Harvard Business School graduates. She encouraged both men and women to be authentic at work. Best advice: "Bring your whole self to work. I don't believe we have a professional self Monday through Friday and a real self the rest of the time. It is …