Mr Hollis, 28, knows how lucky he is to be alive after fighting a rare form of testicular cancer for the last three and a half years.
“Water polo saved my life. If I was an average Joe sitting around the symptoms may hot have been spotted and I could have been a lot worse off than today,” he told SBS World News.
His cancer fight recently saw him claim the Ian Thorpe medal at the New South Wales Institute of Sport awards.
But as proud as he was to win that vote of confidence and admiration, he said his focus is on competing in Tokyo.
“Beating cancer was something special but I want to do one better and go the Olympic Games in Tokyo in 2020.” he said.
He’s already forced his way back into the national team at this year’s World Championships in Hungary, where Australia finished in 7th place – the country’s best finish since 2003.
When he was first diagnosed in 2014, that achievement seemed a long way off.
In the dark days of his cancer therapy, he said the support of his parents and three elder brothers was vital.
Mr Hollis said he was also grateful to the Red Kite cancer organisation for their support during his fight.
Despite the challenges, it seems whatever Mr Hollis turns his hand to will one day lead to success, no matter how tough the obstacles.