"I was looked after by my coaches, but I cried when I had to say goodbye to my mum at Hong Kong airport," Karen says. She was referring to the time when she left the city to compete in the 2005 Special Olympics World Winter Games in Nagano, Japan.
"It took me some time to learn how to be independent," says Karen, who was the youngest athlete at the event.
Karen, 17, is a Form Five student at Hong Chi Morninghill School (for mildly mentally disabled primary and secondary students). She is a winner of this year's A.S. Watson Group Hong Kong Student Sports Awards.
The young athlete at the 2012-2013 Hong Kong Student Sports Awards presentation ceremony. Photo: A.S. Watson Group
She took up winter sports when she was just eight years old.
"I first joined the snowshoeing event, where an athlete runs on snow with their snowshoes on," she says.
"Since there is no snow in Hong Kong, our team could only train on the beach to prepare for competitions."
After training for a year on sand, Karen joined the Hong Kong delegation for the 2005 Games in Nagano, and entered two snowshoeing events.
"That was the first time I saw snow," she says. "I found it more difficult to run on the snow than on the sand."
Not only did Karen feel homesick, she suffered from fever brought on by the cold weather.
However, the illness did not discourage her.
She ended up winning two bronze medals after competing against much older and more experienced rivals.
Back in Hong Kong, Karen's coaches were impressed by her balancing skills. They thought she could do even better in short-track speed skating.
So, soon after the 2005 Games, she switched to speed skating, and almost instantly fell in love with the sport.
"[Speed skating] is much faster than snowshoeing," she says.
"I really love the breeze on my face: it tells me how fast I am going."
Karen was selected for the Hong Kong team in 2007.
Two year later, she represented Hong Kong at the Special Olympics World Winter Games in Idaho, in the US, where she won one silver and two bronze medals.
Karen Tam has been taking part in winter sports since she was eight.
Photo: Hong Kong Sports Association for the mentally handicapped
Some star athletes may relax after winning many medals or major competitions, but Karen is not one of them.
"I always have higher goals for myself," she says. "I used to be a badminton player and I trained three days a week. But to focus on my skating preparation for this year's Winter Games, I gave up my badminton training."
At the Special Olympics World Winter Games held in South Korea earlier this year, Karen won three gold medals and two silver medals in short-track speed skating.
That was her third Games, and it could have been the perfect ending for her career, but the young athlete insists that she will continue for a few more years.
Karen has come a long way since she first started, and is now more confident and at ease.
"Speed skating is really important to me, as it has been a crucial part of my childhood and teenage years," says Karen. "It [also allows me to] bring glory to Hong Kong. So I will strive for more [honours], while trying to increase my speed."