“It was always a dream but I never really thought it could be a realistic dream,” says Cheng, 23. “I wouldn’t say I swam extremely intensely – I just loved swimming, hanging out with friends, being part of a sport.”

Another star swimmer in Beijing was Natalie Coughlin, who became the first US woman to win six medals at an Olympics. Even when Cheng followed her into the University of California, Berkeley, swim team a few years later, the Games still seemed a distant prospect.

WATCH: Camille Cheng’s Road to Rio

“I walked on to the team and didn’t really know what I was getting myself into,” says Cheng, who had missed the intense US college athletic recruitment process while in school in Beijing, and only emailed a few teams at universities she was applying to anyway on the off-chance they’d consider her. “I didn’t know how good a time [for the team] it was, any of the history, that the coach had been selected to be head coach for the US Olympics team ...

“One day I was sitting in my friend’s apartment looking through her photo album and was like, ‘You went to the Olympics?’ She was like, ‘Yeah ...’ and I was like, ‘You got a medal?!’ She’s like, ‘Yeah ...’”

That friend was Sara Isakovic, who Cheng might have seen in action in Beijing – she won a silver medal in the 200-metre freestyle for Slovenia before going to California to study.

“She was so humble about it,” says Cheng. “Over my four years there, it was just the right environment for me to start believing in myself and I improved a lot in my times.

“I think my junior year I had my breakout summer and that’s when I dropped a lot of time and was like ‘I’m just going to give it all I’ve got’ [a bronze at the 2014 Asian Games followed].

“I graduated last year and decided to do full-time swimming and nothing else, just to focus and give it my best shot.”

In December last year, that paid off when Cheng made the Olympic ‘A’ time – guaranteeing a place – in the 200m freestyle at the US Nationals. She also has the B standard – which allows an athlete to picked at the national selectors’ discretion – in the 100 and 50 free.

Until recently, University of Michigan’s Siobhan Haughey was the only Hong Kong swimmer ever to have made an Olympic A cut, but HK have three for Rio, with another Berkeley alum, Yvette Kong Man-yi joining Haughey and Cheng.

“I’m really excited because I think a lot of people now on the Hong Kong team are swimming really well,” says Cheng.

She was back in Hong Kong in part to try to help the relay team – Kong, Cheng, Stephanie Au Hoi-shun (another Berkeley grad) and Sze Hang-yu – qualify for Rio in the 4x100m medley relay at the Malaysian Open. The top 16 in the world on May 31 qualify; at the moment HK are in, but they could be pushed down after the European Championships this month. It’s a similar story in the 4x100 freestyle relay.

Multilingual Cheng, whose father is from Taiwan and mother from France, can’t speak Cantonese but, after being made joint captain at Berkeley in her final year, will still be doing her best to inspire her teammates in Rio.

“I wouldn’t have thought I would have been a captain,” says Cheng, who was born in Hong Kong and attended French International School until her family moved to Beijing for her engineer father’s job when she was nine.

“My freshman year I was very shy, very quiet. I wasn’t as experienced, didn’t know as much about swimming. I think throughout the years you see what type of leadership is on the team, from coaches staff, other teammates and captains.

“I found my way to lead in a different way. I wasn’t as loud but when I did say something people would listen. I tried to lead by my actions, not so much by my words.

“I think a big thing was I used a lot of my experiences to try and relate to and connect to everyone on the team: being an international student, and also I take academics very seriously, dealing with not being as good of a swimmer and then really improving a lot and then struggling, ups and downs. I found a way to help share that with the younger people as I got older.

“If I see someone struggle, I’ll reach out and let them know that I’m there if they need anything. It really helps for people to know that people have gone through similar feelings and to be able to relate in that aspect is comforting.”

And the psychology graduate hopes lessons learnt in class can transfer to the pool.

“My first two years I struggled, I just felt I didn’t really belong on that team being surrounded by such great swimmers. I felt like I was taking away and not contributing anything, but I took it as motivation to work harder. I had a lot of self-doubt and confidence was a big thing – I didn’t have that much but that’s something I’ve gotten way better at dealing with.

“Before, I was not really open to talking about my problems, however big or small – once I let people in I found that most people are definitely willing to help and that’s where you find really strong relationships and friendships.

“I took a lot of personality and social psychology classes: more how to work on a team, how to work with groups. I took a positive psychology class, more for fun, but definitely learned different techniques: ‘power posing’, the power of positive self-talk. If during practice all your teammates are like, ‘This sucks,’ obviously it’s not beneficial, [and you need to know] how to quickly change that mindframe.”

For Cheng, who also led a class at university for female athletes focused on leadership in sport, being part of a team in Rio could be even better than the individual laurels.

“It might be the first time Hong Kong send a relay to Olympics and the fact that we can have four girls compete, it’s all about the team,” she says. “I think relays are always the best part of swimming. I really hope at least one of relays qualify just to able to represent Hong Kong as a team.

“Hong Kong is a little smaller group [than other national teams], but if we can make our presence felt in Rio, I’d just be really proud of that.”