Gabrielle Douglas: It seems to happen every four years: A U.S. gymnast you've never heard of heads to the Olympic Games and, in only a few days, wins over America's heart. Gabrielle Douglas did that in 2012 in what was arguably the most popular all-around win for an American since Mary Lou Retton did it way back in 1984.

Gabrielle Douglas: It seems to happen every four years: A U.S. gymnast you've never heard of heads to the Olympic Games and, in only a few days, wins over America's heart. Gabrielle Douglas did that in 2012 in what was arguably the most popular all-around win for an American since Mary Lou Retton did it way back in 1984.