Gary, a Form Five student at Liu Po Shan College in Tsuen Wan, started race walking at the Alexander Athletic Club in April.
"I had been training only for a week before I took part in my first race," he recalls. "In the following months, I started winning some medals in other local races."
In October, Gary competed in a 5,000m race at the Hong Kong Race Walking Competition. He finished with a time faster than the current Hong Kong junior record. Yet his achievement was not recognised by the Hong Kong Amateur Athletic Association as he was one of only two runners in that race. That didn't meet the minimum-three-participants requirement for claiming a new record.
So there was a case of both an up and a down right there. Undaunted, Gary set his sights on winning more medals to add to his haul of just two trophies.
Next up: the 1km MTR race at Chater Road. Gary was in the lead, and as he was nearing the finish line, he raised his hands in celebration. But as he did so, he failed to keep at least one foot on the ground, and was disqualified. "It was heartbreaking to see the champion's name written on the board was not mine," he recalls.
Another case of an up and down at the same time. It didn't improve matters that many people who thought he had won came to congratulate him.
The saddest moment was when he walked past the stage for the prize presentation. "Even though I had since been disqualified, there was a recurring broadcast of the 8am news, showing me celebrating. It was being replayed on a gigantic screen. I looked at my happy face and listened to the victory speech I had given to a TV crew an hour before. I couldn't tell you how unhappy I was," Gary says.
Gary headed home and stayed in bed for a whole day, hoping to erase the memory of his embarrassment. He began to feel better - only to have his friends congratulate him at school the next day. They still didn't know he had been disqualified after the race.
A friend had uploaded the news coverage of Gary's "victory" to Facebook. "I didn't know how to explain it to them so I put up a show of being a winner," he says.
So here it was: tragedy and comedy rolled into one. But Gary did not let the incident keep him down for long. "I understand that I am still a beginner in this sport and it is normal for me to go through ups and downs," he explains. "I am more determined than ever to succeed and become a true champion."
He has picked up the pace of his training. He speed-walks and jogs 70 to 80km a week. "With hard work, I can become more mature so I won't commit the same mistakes again," he says.
His zeal and stamina have already paid off. Last week, Gary finally claimed his first major achievement by winning the 10km race at the Hong Kong Road Race Walking Championships 2012. He broke the local junior record in the process.
Now at last he has a trophy he has been longing for. And perhaps more importantly, he has gained something else as well: valuable experience.
"I am still just starting out," the young champion says. "I believe there is a bright future ahead and lots of new targets for me to achieve."
He adds: "Failures may get me down, but I need to get back up and carry on."