Roger Federer says it is his love for tennis that allows him to keep performing at such a high level 15 years on from his first Wimbledon title.
The Swiss kickstarted an astonishing grand slam career with victory in 2003 at the All England Club, where he has since won another seven crowns.
And Federer looks well placed to contend again this year after a sublime second-round defeat of Lukas Lacko on Wednesday, following which he explained how he has been able to stay at the very top of the game.
"It's been good. I've never fallen out of love with the sport. I think that's been helpful, too," he said. "I've kept the [ATP] Tour fun.
"Obviously, in the last nine, 10 years now, since we have had children, I've been trying to make that work in some shape or form with my wife. It's been a lot of change in the last 15 years, no doubt about it.
"I think we have come through it well."
Federer's serving was particularly dominant against Lacko, as he raced through games in the second set without dropping a point, and he attributed his success rate to his consistent application.
"I think what is important when you want to serve well is your point-for-point mentality, saying maybe the first point is as important as a break point," he said. "So the concentration is the same."
It is a process he would advise Switzerland's national football team take, too, having been disappointed by their last-16 World Cup defeat to Sweden.
"It is important they understand that you have got to bring the energy every single day," he said. "It's throughout the year, it's not just in the World Cup, last 16 or quarters.
"That's why you need to bring it every single day.
"When you step out on the pitch, or on the court in tennis, in practice, in the match, you have to always try to be be able to be as high as possible. Then it's actually not a big deal to bring it also in a match like yesterday."