( CNN ) -- He was just 4 years old when his treatment sparked international outrage . About a year later , he won an award for the world 's youngest sailor . And he piloted a plane before he turned 6 . Up next ? Crossing the Tibetan Plateau by unicycle . Welcome to the unorthodox and controversial world of Duoduo and his `` Eagle Dad . '' The world first met little Duoduo , as he 's nicknamed , in 2012 . A video surfaced of his small 4-year-old frame shivering in subfreezing temperatures . `` Daddy , Daddy please hold me ! '' Duo cried into the camera . His tiny body was shielded from the cold and snowy New York winter only by bright yellow underwear and a pair of white sneakers . His family was in New York on vacation , but there 's no time off from training when you 're the son of He Liesheng . That video drew criticism and some praise from around the world . But He did n't mind . He says he knew what he was doing . `` I 've always felt Chinese parents spoil their only child too much , '' he told CNN at the time . `` We do n't expose them to nature enough , and they get weaker and less competitive compared to foreign children . '' He , who dubbed himself Eagle Dad , did n't just want his son to succeed , he wanted him to soar . `` Like an eagle , I push my child to the limit so he can learn how to fly . '' Two years later , the duo have made good on that pledge . At their high-end apartment in Nanjing , certificates from Chinese authorities line the walls , and there are world records : There 's one for the youngest person to start an investment company and one for the youngest pilot . The latter acknowledges Duoduo 's 30-minute flight near Beijing at an altitude of 1,000 feet . Also posted on the wall : spreadsheets and documents that detail Duoduo 's daily schedule . The precocious 6-year-old rises at 7 a.m. , but only on his holiday . Normally , he wakes up at 6:30 . But even the world 's youngest pilot gets a day to rest . `` On Sunday , I can even watch movies . '' Duoduo says . The energetic child , who happily speaks his mind and tears around the apartment , stands in sharp contrast to the child the world first saw crying and upset in the snow . Looking back on that day in New York , Duoduo remembers the cold , but he also remembers what came next . `` When I was running nearly naked , I kept crying . And then dad gave me a hot bath . '' For his part , He says there 's more to their story than the extreme images . Yes , he made his son run in the snow , and he also took him skiing and made him take cold baths . But there were less dramatic scenes , too . The family focuses on education , He insists , and the tough stuff has a purpose . `` If a child does not go through hardship , then he can not become strong , '' he explains . `` That means when they are small , you should let your child struggle more , allow them to experience more , and it is good for their development . '' Their life is n't all struggle , though . Duoduo lives comfortably and hopes to grow up to become an entrepreneur like Bill Gates `` because you can help other people and you can buy a lot of things . '' And what does the boy himself think of his Eagle Dad 's methods ? `` The good side is that I can learn a lot . The bad side is that he 's just too strict ! ''
He piloted a plane and started an aviation company by age 6 . His father also made him go outside in freezing cold wearing just underwear and shoes . ` ` Like an eagle , I push my child to the limit so he can learn how to fly , '' his father said . ` ` If a child does not go through hardship , then he can not become strong ''