Mollie O’Callaghan admits there were moments she struggled with her sudden ascent. Yet today can only smile as those around her wonder just how good one of the faces of swimming’s new world order can become.

The 18-year-old freestyle star is now turning heads in backstroke after she so nearly pipped Australia’s Olympic and Commonwealth champion Kaylee McKeown in a 100-metre event in the Duel in the Pool at the Sydney Olympic Park Aquatic Centre.

O’Callaghan finishes with such a flourish that she is building a reputation as a stone-cold assassin in the water. She mowed down Shayna Jack and Emma McKeon - Australia’s greatest Olympian, no less - to add a Commonwealth title to the 100m freestyle world title she claimed in Budapest in June.

That Birmingham triumph marked one of five gold medals O’Callaghan claimed at the Commonwealth Games, adding them to the haul of two golds and a bronze earned in Tokyo a year ago.

“It’s kind of hit me so fast,” O’Callaghan said. “Last year to be honest, it was just nothing. I went to the Olympics and started building my way up. All of a sudden, this year it’s all hit me in one go. It’s been a bit hard at the start, especially before worlds. I struggled a lot mentally after trials to get back into the rhythm and enjoy swimming. I guess the pressure got to me.”

But now you would struggle to wipe the smile from her face as O’Callaghan talks about the thrill of racing a “great inspiration” like McKeown, or the impact of her 28-year-old relay teammate Madi Wilson.

“She’s probably one of the biggest role models for me,” O’Callaghan said. “We swim in the same races, and she would walk me to marshalling for my 100m free for worlds. I really liked that, because I didn’t have Shayna or anyone else with me.

“Before that, I was again struggling mentally. I was very nervous and everything was getting to me. I just found that helped a lot. All the girls are very inspirational. You always have someone to look to in Australian swimming.”