Rio de Janeiro, almost 11 months ago. Under the sleeves of Memphis Depay’s polo shirt, big biceps pop out. It impresses me, even though the then 20-year-old has shown them so often on Dutch TV after matches. Or on his Instagram.

He is happy for the world to peek at his Tarzan torso on which there is more green than in an average forest. He even has a tattoo saying “successful” on the inside of his lower lip. Is he an exhibitionist? A showman? He is just himself, he answers. Depay sounds bemused: “But if you want to call it that, you can call it that”.

The chat takes place during the World Cup, his first one. It is winter in Brazil but the evening chill seems to bounce off those biceps. Just like the tension of matches, the increasing attention of the press and the enthusiasm of the fans here and in his home town of Moordrecht. “I have no stress. I’m never nervous,” he says. “What can stress do for me when I play? Nothing.”

We talk about the connection with Louis van Gaal, then the coach of Holland. Depay is enthusiastic: “Van Gaal invests in me as a person. He is genuinely interested in my background, my thoughts, my ambitions, what I like to do in my spare time. He can be tough and demanding on the pitch but I need a coach that’s on my back. Off the pitch I’d rather describe him as a sweet person.”

Between matches the showman, who scored two World Cup goals and climbed above Jeremain Lens and Klaas-Jan Huntelaar in the team’s pecking order, modestly soaks up information from Van Gaal, Arjen Robben and especially from the captain, Robin van Persie. He refers to Van Persie not as an example or a team-mate but as “a friend”. The captain had spoken highly of him before the tournament: “He often sits at the table with the older players. He is very eager to learn things.”

A month or so later the Koeman brothers, newly in charge of Southampton, tried to sign Depay from PSV, in common with many other clubs. “He is fast, strong and always aiming for goal,” Erwin Koeman, assistant to his brother Ronald, said. “It would be a great opportunity for Memphis to get used to England at a smaller club with two coaches who know him and have a lot of confidence in him. Depay turned us down. A pity for us but also for him.”

The flamboyant forward probably has not forgotten what Ronald Koeman said about him a year earlier. “Depay walks around like he has won 10 European Cups. This attitude … what’s it all about?”

Other former players were critical. Wim Kieft, a former Ajax, PSV and Holland striker who worked with a young Depay at PSV, had big doubts about the player’s mentality. Kenneth Perez, a former Ajax and PSV playmaker, sometimes thought Depay was “totally crazy”.

Depay responded calmly: “I’ve read everything they said. What can I say? They don’t know me.”

His desire to become the world’s best is a bigger fuel than criticism. Depay can wear an angry expression after a PSV victory in which he has scored because he also missed a big chance. The Dutch Ronaldo some call him, though Depay is always genuinely happy when a less prolific team-mate scores, even if he was in a better position.

His coaches at PSV, Dick Advocaat (now at Sunderland) and Phillip Cocu, hail Depay’s work rate. “Always the last one to leave the training pitch,” Advocaat said. “Always improving his qualities, never scared to attack any opponent. He has everything to become a top player.”

Cocu said: “Physically he won’t need any adaptation for a bigger competition. He’s got great stats and even if he doesn’t score or assist he’s always dangerous and works for the team.”

For a long time it looked as if Depay would never push the right buttons to even become a professional. At four his Ghanaian father left him and his Dutch mother. His mum met a new boyfriend who had a bad influence on the atmosphere at home. Memphis (the name he prefers on his back to that of the man who abandoned him) started to rebel, worshipping the pseudo ghetto culture in Rotterdam and putting a lot of energy into his rap group, Rotterdam Airlines.

At Sparta, a successful talent factory, they could not handle him. Kevin Valkenburg, a development manager at Sparta, said: “Memphis wasn’t an easy boy. He was difficult to correct, like there was a wall around him. At Sparta he was close to his old environment. PSV has been his saviour, I think.”

PSV, where he arrived aged 12 and who put him with a family, hooked him up with the life coach Joost Leenders. At first he did not respond but their understanding grew into a friendship, with Leenders constantly urging him to consider “the consequences of his deeds”. Leenders also asked him what he thought was most important. They came to the conclusion it was football, football and football. Everything else should be secondary to his ambition: be one of the world’s best.

A month after that impressive first World Cup Depay signed a new contract at PSV, much to the surprise of everyone, including his agent. “I have to make one more step,” Depay said. “Become a champion, be important.” Though not always showing his best form he unquestionably established himself as the top dog and leading scorer with 21 goals. Van Persie, his mentor, scored only six in his final season in the Netherlands.

Given Depay’s understanding with Van Gaal it was no surprise that Manchester United beat Liverpool and Paris Saint-Germain in the battle to sign him. Memphis is more powerful than Adnan Januzaj and Ashley Young, quicker and more penetrative than Ángel Di María, worries less than Marouane Fellaini, is more mobile than Radamel Falcao and Van Persie and has a better right-foot shot than any of them.

One thing is certain: no forward at United will be more loyal than Depay to a pet. At the end of that chat in Rio he said he missed his Chow Chow Simba, who was “just as loyal, sweet and pigheaded as his boss”. Hastily, the most extravagant player of Oranje corrected himself: “Oh no, make that ‘friend’.”

Bart Vlietstra is a football reporter for the Dutch newspaper de Volkskrant