China Daily reporter Guan Xiaomeng is an avid fan of Liu Xiang

I was listening to one of the theme songs of the 2008 Beijing Olympics on my mobile music player while lying on a beach in Saipan, sipping a glass of orange juice during my annual leave when I heard that Liu Xiang is retiring.

Welcome to Beijing ... a moving piece of music ... the lyrics of the then most popular song, though heard thousands of miles away and seven years later, set my pulse racing much as it did then because that was the very Olympics when I learned to be a grown-up sports viewer rather than a schoolgirl crush fan - thanks to Liu.

From his rise to prominence at the 2004 Athens Games, to setting a 110 meters hurdles world record, his shock retirement from his home track in 2008 and leaving early from another Olympics four years later, to today's decision to say good-bye, Liu's ups and downs mark each milestone of his hurdling career. I hope China learns from its handling of a favorite athlete and sports at large – showing tolerance of failure and paying attention to other athletes. Today's lesson, I hope, should be the end of the puberty of China's sports.

A grown-up has a clear estimation of oneself. To give up does not necessarily mean to lose. Yao Ming retired from the basketball court but now wields even more influence; Li Na hung up her tennis racket at a right time having since earned more fame.

For Liu, some believe the 2008 turning point was the right time to quit so the added disappointment of 2012 should not have repeated. I can't agree more. Speculation of either marketing considerations or to save face for the "national system" should not be reason enough to override the athlete’s health. I am no expert on kinetics and not sure whether there have been problems with his training or the treatment of his injured Achilles' tendon. But to push him to the start line of the most anticipated Olympics while knowing full well that he couldn't make it is cheating.

A grown-up should not be "willful". This word became popular after Premier Li Keqiang used it in this year's government work report to warn staff against the illegal use of power. A grown-up sports viewer doesn’t have the power to get whatever they expect from athletes. Liu Xiang is flesh and blood, not a machine to satisfy others.

Judging an athlete purely by winning and losing is not right because to over compliment a triumph yet maliciously attack shock retirements from the two Olympics are self-contradictory. Sporting success sometimes depends on luck, which is not controlled by human beings.

A grown-up has to learn to share and appreciate. Some people doubted Liu's triumph came against the very best as there were a number of faster men from around the world and even some better home talents not competing against him.

I am concerned for the future of sport after seeing Liu retire as his possible national successors don't appear strong enough to take up the mantle. Is the old era going to end without a new one unfolding? Luckily, football in China is embracing the start of its adulthood, or at least showing the willingness to grow up. Evolution within the sport's governing body based on the market instead of self-willingness is heart-warming. I am not saying track and field should follow suit as different sports have different ways of developing. But Liu's lesson is deep enough to teach us to face the truth rather than live in the past.

Growing pains are inevitable. During puberty we are subject to changing moods while when growing up we must keep our head.

I really loved Yao Ming's answer to questions concerning how a "star member" influences the county's top legislature (NPC) and political consulting body (CPPCC) during this year's two sessions. "I am not a 'star'now but a CPPCC member. Being a 'star'is my past and please pay more attention to what I am doing now."

Whatever Liu is going to do after today has nothing to do with his past. All his ups and downs will turn out to be past stories, touching the pulse of people like me who have been watching him over the years. Like the sapphire blue seawater of Saipan - within reach now but becoming memories all too soon.