Gabon and Borussia Dortmund striker Pierre-Emerick Aubameyang is always improving, says coach Thomas Tuchel.
The 26-year-old has scored 30 goals for the German side this season and earlier this year he became the first Gabonese to be named the Confederation of African Football player of the year.
"Becoming Africa's player of the year was extraordinary, a huge prize," Tuchel told BBC Sport.
"It made him stronger, even more self-confident."
Tuchel added: "Players like 'Auba' improve themselves with their spirit, their mentality and their will to give everything, every day.
"He plays to become a league top scorer, to get a hand on a cup or championship trophy."
Aubameyang's journey to the top has not been without difficulty. After coming through the youth system at Italian giants AC Milan, he was offloaded without playing a game.
Similar rejection then followed in France, the country of his birth, during a sequence of unproductive Ligue 1 loan deals.
Like so many Africans before him, it was at St Etienne where the then slightly-framed West African finally found his feet.
The early setbacks were formative, though, equally so the highs and lows of an Africa Cup of Nations on home soil in 2012.
Dortmund captain Mats Hummels, a World Cup winner with Germany, says his club-mate has "plenty of qualities", but singles out the forward's deadly acceleration.
"He is the fastest player I have played with or against," he said. "He also works hard for the team, which is the most important thing."
However, Aubameyang's selection as football of the year was criticised by his four-time predecessor Yaya Toure.
"What Toure did was quite outrageous," says England-based German journalist Michael Streck of the Manchester City midfielder.
A Dortmund native, Streck tracks the Bundesliga and Premier League.
"Aubameyang has been playing at a world-class level for several years now," Streck said.
"This year Dortmund have been playing a more possession-based style than they had under Jurgen Klopp and I think Aubameyang has benefited from that, too."
Tuchel refuses credit for the most prolific season of the forward's career, however.
"I'm happy that we have a good connection, that I can help him, try to guide him on his way," he said.
"But it is his way, it is his talent and it is his achievement."
With the Bundesliga to fight for and another Africa Cup of Nations in Gabon next year, Germany and all of Africa are watching to see how far Aubameyang can go.