There is a pressure, spoken and unspoken, for All Blacks to "leave the shirt in a better place". It is a maxim that compels New Zealand's rugby players towards continual improvement of themselves and others, be that at international or club level. And no All Black has stood up to this challenge more than Dan Carter, who is about to take that approach with him to Japan and the final stage of his playing career with Kobe Steelers.
Carter has already left things "in a better place" throughout his playing days. He did that with the No. 10 shirt of New Zealand and Crusaders, his Super Rugby home for 12 years. His record -- double World Cup winner, three-time Super Rugby winner and leading points scorer in international and Super Rugby history -- speaks for itself.
He did the same at Top 14 club Racing 92, and not just by guiding the club to their first French title since 1990, as well as their first two European finals. Carter left Racing this summer to resounding tributes.
"You've got to be with a guy every day to appreciate what he brings, how he is as a man," Ronan O'Gara, the former Racing coach now at Crusaders, told ESPN. "In my mind, since the game has been professional, he must be seen as the best out-half ever to play the game."
Carter headed to France in late 2015 after winning a second Rugby World Cup. He considered England's Premiership for his next stop, "but I loved the challenges that come with playing in France."
From the outside looking in, he had nothing left to prove. But Carter himself remembered 2009, when a ruptured achilles had cut short a stint at Perpignan after five games. He wanted to give French rugby another shot.
"I wanted to play for more than six months," Carter told ESPN. "Although I didn't get to play a lot, I saw how much the Bouclier de Brennus [the trophy awarded to the winners of the Top 14] meant to the supporters, to the players.
"I had aspirations of playing in the European Championship as well. I had to be selective about which team I decided to go to -- Racing was the perfect club."
However, distilling years of experience into something the French would buy into was never going to be easy. O'Gara joined Racing as defence coach two years prior to Carter's arrival. He described supposedly professional standards as "poor", highlighting the "tubs of mayo and butter and Coke on the table" at players' lunches. "There are so many good things about French rugby, but so many other things that can be improved," added O'Gara.
"As well as being a great player, Dan Carter is a great man" coach Laurent Labit told Le Parisien earlier this year. "He made us all grow up."
One comment in that interview, though, was telling. "Dan found in France not many players are into sharing knowledge. And young people are not all willing to be told things."
Carter admitted as much to ESPN: "You have to try to fit into the culture and the way things are done in France.
"You can't change it. I had a couple of moments where I felt like banging my head against a wall. But you can slowly implement certain things, or give advice to players and make them think differently."
Racing teammate Yannick Nyanga was won over. "He [Carter] led naturally, without forcing his personality on us," said Nyanga. "His attitude, both in games and training, was exemplary, and his simplicity outside was an example of what a great player is.
"In important moments he also brought calm, serenity, and perfect management of emotions."
Leadership groups have been a feature of southern hemisphere rugby for years. They've caught on in the north now, too. But, when Carter arrived at Racing, they were almost unheard of. So he created one.
"Its mission was to deal with group life and the team's overall performance. He challenged coaches, too, for the good of the team," added Nyanga, a member of the leadership group that Carter formed. "He created an operation where the team is at the heart of everything."
In no match was this more evident than in the 2016 Top 14 final against Toulon. Carter kicked five penalties and took personal charge of the game after Racing's Maxime Machenaud was sent off early on.
"After the Rugby World Cup in 2015, I thought nothing would get close to that feeling," said Carter. "But to play [the 2016 final] in Barcelona in front of 100,000 people, to help Racing win their first Top 14 title since 1990, that was special."
As Carter and Racing led, others have followed. Over the past two seasons, Christophe Urios, who coached Castres to the title last season, has made a big deal of his "council of elders", which was key to Castres' success. The players even used Racing's Carter-led Barcelona performance as a paradigm of 14-player game management against arch-rivals Toulouse after Jody Jenneker saw red with 20 minutes to play.
There was one cloud that hung over that Barcelona triumph, however. Carter and wingers Joe Rokocoko and Juan Imhoff reportedly tested positive afterwards for corticosteroids before being cleared by the French Rugby Federation. There was also a drink driving charge in 2017, which Carter said he felt "pretty sick" about. "It wasn't all smooth sailing [in France]," Carter told ESPN. "But you learn from those setbacks."
His focus now is on his two-year deal with Kobe Steelers. "I'm really excited. When you've been playing as long as I have, you need these new challenges to motivate you."
As for Carter's legacy in France, O'Gara brings it back to titles. "He won two Boucliers. There are players who have played 15 years, who are legends, who have never won a Bouclier."
It's more than that. He left the Racing No. 10 shirt, the club and the Top 14 in a better place.