Sonny Bill Williams has won two Rugby World Cups, been named the best rugby league player in the world and won the New Zealand heavyweight boxing title.
But there is still a hole in his sporting CV. A hole that can only be filled by five big rings.
"Going back in time the best sportsmen ever have been Olympians," said the 30-year-old as he announced he would dedicate himself to being part of rugby sevens' debut at Rio 2016.
"Usain Bolt, Muhammad Ali, the list goes on. It's just an amazing opportunity to become one of those."
This weekend is the start of that journey as Williams - a little more than a month after lifting the Webb Ellis Cup - heads to Dubai for the first event of the globe-trotting Sevens World Series.
This is not one of six World Series events that Williams aims to play in. Instead he has cut short his off-season to meet his new team-mates and learn the seven-a-side game from the sidelines.
And he is not the only 15-a-side star aiming to be part of rugby's new frontier.
Olympic sevens: Sonny Bill Williams starts the rush for Rio 2016