Samuel Eto'o has admitted he thought so little of José Mourinho after their first encounter that he could never foresee a professional relationship being forged between the pair. Speaking in a week he could, injury permitting, make his debut for Chelsea against Everton under the Portuguese manager, Eto'o revealed: "I must say that when I first met Mourinho, I never thought I was going to work with him. I got it wrong and if I am not mistaken, I believe I said that publicly."

The Chelsea striker and his new manager famously clashed following a fractious and controversial Champions League last-16 second leg encounter at Stamford Bridge in 2005, when Eto'o, then with Barcelona, denounced the sideline antics of Mourinho, then in his first spell at Stamford Bridge, as "shameless" and confronted him, saying : "I know you are a great person and a great coach but in truth you are just a shit." He had reportedly said before the match that "I'd rather sell groundnuts in my village than to play for a pathetic team like Chelsea", and went on to describe the English club's win as "a disaster for football" and threatened to retire if they won the Champions League. They did not, as Liverpool beat them in the semi-finals en route to a memorable European triumph under the stewardship of Rafael Benítez, another future Chelsea employee with form in the field of publicly disparaging the club.

"Everybody has an opinion on José without actually knowing him," Eto'o said this week, having revised his opinion during a successful spell in Italy when the headstrong duo joined forces to help Inter win the treble of Champions League, Scudetto and Coppa Italia. "I say thanks to God for giving me a season with him at Inter. We both understand that we were born to win together, so it is a good thing."

Quizzed on the difference between the man he labelled "a shit" and the one for whom he took a £12m pay-cut upon his release by Anzhi Makhachkala, Eto'o suggested the occasionally arrogant, spiteful, petty and often paranoid version of Mourinho with whom many are familiar is a media caricature. "I cannot put myself in journalists' shoes, who must sell what is good and bad to people," he said. "It's their job. Me, I see José Mourinho as a man and I know which things are true." Eto'o went on to reveal that Mourinho's return to Chelsea was the deciding factor in his decision to come to London. "I would say 60%, with the rest being the great players who are there," he said. "The best group of players in the world."

The Cameroon international was speaking at a publicity drive for his comic book Eto'o Fils: Nacimiento De Un Campeón" (Birth Of A Champion), the first of nine issues which chart his rise from impoverished street urchin on the streets of Douala to the world's highest-paid footballer, African icon, anti-racism campaigner, philanthropist and occasionally spiky enigma. Talking to journalists a day after he is believed to have retired from international football (a matter on which he refuses to comment) and shortly before he was criticised for selfishness, cronyism and lack of effort by his former Anzhi team director Roberto Carlos, this notoriously difficult interviewee looked happy as he sat alongside Joëlle Esso, a musician and artist from Cameroon who the footballer approached to illustrate his comics because his children love her work.

"I want to share my story with youngsters and show that this story, which they dream of, began with someone who was very poor, but who had the idea they could reach the top by working day after day," explains Eto'o. "I was expected all the time to challenge the best so I want to encourage others to do the same. I think it is even better in a graphic novel because people can identify with them. Even adults read them, but my original idea was for it to be aimed at children. The most important thing in life is to share with others. If I am very rich, have no friends and do not truly share things with others, then ultimately I am poor. It is very important to see smiles on the faces of all those around me."

Eto'o's collaborator Esso, when asked about the pressure of having to deliver at the behest of her country's most famous son, concedes that it was "enormous", but reveals that for all the accusations levelled at the footballer by Carlos and others over the years, her compatriot is at least not vain. "He made me change his ears," she laughs, as beside her Eto'o grins and pulls at the distinctive appendages protruding from each side of his head for comic effect. "He said I did them too small and they are bigger."

Eto'o is reluctant to talk about the excellent charitable work done in Cameroon by his foundation because "it's a personal thing" and "getting things done" is more important than being perceived as a show-off. Unfortunately for those of us invited to speak with him, he is equally reluctant to discuss football because he is here to publicise his book, from which all proceeds raised will go to the aforementioned charity he has no great desire to discuss.

A man of few words, then, but one who becomes enthused upon being asked how he is finding life in London. "I already knew it," he says. "I have never lived here but I used to come with my camera and my cap down and go incognito in the streets. It's a good city." When asked if it will be the final destination of a remarkable football journey, Eto'o is noncommittal. "As long as I can run and as long as I get pleasure from playing, I will play forever," he says, echoing a sentiment first aired by his nine-year-old self while selling fish by the roadside in Douala.

• Volume one of Samuel Eto'o's comic-book autobiography, Birth Of A Champion, is out now. All proceeds go to the Samuel Eto'o Foundation.