"If you sleepwalk your way through life, you won't survive," says Chelsea manager Emma Hayes. "Complacency, the mother of all devils, creeps in, and then it's goodnight." She is talking about defender Jess Carter in the documentary One Team, One Dream. The year is 2019 and Jess has failed to fulfil her early promise. "What are you waiting for?" Hayes asks. "It's up to you to decide your future."

"For a long time it felt like that would be Carter's story in English football," writes Jonathan Liew in The Guardian: "a tale of squandered talent and unfulfilled potential, a gifted athlete who perhaps didn't quite want it enough... Carter had always craved success, but perhaps lacked the confidence to commit fully to it."

But as this year's World Cup showed, things have turned out otherwise.

Carter grew up in Warwick, the daughter of an American father and English mother. Tragically, her mother suffered from alcoholism and abandoned her when she was a baby.

Her talents became obvious at a young age. "She started kicking a ball around aged three or four," says her first manager, Dan Brandrick. "Her brothers trained with me and then when she was around six she came along too.

"From the off she was obviously so strong, athletic and talented. She played in midfield for us and she was as good or better than all the boys... She won't score fancy goals, but she is the heartbeat of any side."

At 16 she made her first-team debut for Birmingham City against Arsenal in the Champions League, and was named player of the match. Soon afterwards she was chosen for the England Under-19s. Three years later she made her first appearance for the senior England team.

In 2018 she joined Chelsea, but struggled to make an impact. During her first three seasons with the club she made only 11 appearances in the Women's Super LeagueEngland's top league for women. Created in 2010, it consists of 12 clubs.. Off the pitch she has had pressures to deal with too, supporting both her sister Amelia and her girlfriend Ann-Katrin Berger through treatment for cancer.

She was, writes Jonathan Liew, "an irresistible mix of bravadoA tendency to take unnecessary risks to show off one's courage. It comes from the Spanish bravo, meaning bold. and vulnerability, a young woman trapped between the urge to feel good and the urge to do good. She was frequently late for training. Club staff consistently warned that she was missing fitness targets." When she was told off, she sulked.

But Emma Hayes was not ready to give up on her. Carter's diet was a particular focus: she had to give up on junk food and follow a strict nutrition plan. She even had to send in pictures of the meals she cooked at home.

During the 2021-2022 season, things finally came together. Carter became a key part of Chelsea's defence and helped her team win the treble. And this summer she showed her extraordinary calm under pressure during the Lionesses' run to the World Cup Final.

"She's really showing her value to club and country," says Hayes. "She's got pace, she's got power, she's got poise, she's got mentality."

Yes: You can be the most talented footballer in the world, but if you do not believe in your own ability you will never make it to the top. Without gaining confidence, Carter's career would have ended prematurely.

No: There are plenty of people who think that they are brilliant at what they do, when in fact they are only fairly good. No one without great skill on the ball is going to play for the Lionesses.

Or... You need both in equal measure, because the two feed off each other. Having talent gives you confidence, and having confidence helps you to develop your talent.