Dani Alves rocks back in his chair, a glint in his eye. “Imagine if I’d been any good,” he says. Imagine. If he’d been any good, he might have made more La Liga appearances than any foreigner ever or provided a hundred assists, more than any other player apart from Lionel Messi over the last decade in Spain. He might have been voted into the FIFPro team five times or won so many trophies that he’s lost count. If Dani Alves had been any good, he might have won five leagues, four cups, three European Cups, three Club World Cups and two Uefa Cups.

Oh, right.

So, Dani, how many trophies have you won? It’s only the second question – the first, in case you’re wondering, is who is the world’s best right-back and the answer, in case you’re wondering that too, is Cafu – and for once Alves is stuck. There’s a pause and a false start before he responds: “Twenty … er, thirty?” Thirty trophies. It’s a number that brooks little argument but with Alves there’s always an argument. Time, then, to make a case for the defence?

Defence? Alves? If there’s one thing everyone “knows” about him, it’s that he prefers to attack.

There’s something about Alves. Maybe it’s the way he plays. Or the way he dresses: today he’s in baggy beige trousers, MC Hammer-style, shoes with metal spikes on, a black T-shirt and jacket tied around his waist, all disappointingly normal. Or the way he is. Maybe it’s the silliness, the singing, the cheek, the outspokenness. Something that wins him admirers, sure, but detractors, too. Something about him gets to them, and they clearly get to him, too.

Maybe it’s the way he talks. Alves talks a bit like he plays. Quick, open, chaotic, seemingly everywhere at once. But there’s an underlying logic there too, a commitment and a seriousness even – for those prepared to look. He cares. It’s an enjoyable ride, carrying you along. He packs a lot in, that’s for sure; and he gets a lot out. Those 30 medals, remember. Which seems as good a place to start this conversation as any, even if where it will end isn’t yet clear. So, here goes: 30 is a lot, but anyone can win medals in this Barcelona team, right?

Dani Alves celebrates with the trophy after winning the Champions League in 2015, his third European Cup. ‘Maybe it’s easy to win a title at Barcelona, but [it’s not so easy] to have a long history here.’ Photograph: Michael Dalder/Reuters

Not exactly. It’s not just that Alves has more medals than all his Barcelona team-mates except Andrés Iniesta or that he led Sevilla to two Uefa Cups and the verge of a miraculous league title. Nor that he and Gerard Piqué were the only additions to a squad that had endured two years of failure, and that his influence in their success was huge. It’s that if longevity at the Camp Nou is often offered up as the sole explanation for success, reason to doubt his value, he argues that his longevity is a success. That’s his value, right there.

And, with that, he’s off. “Maybe it’s easy to win a title at Barcelona, maybe it is,” Alves concedes. “What’s not is to win so much, to have a long history here.”

Alves knows. The demands are relentless. Every season some want it to be his last, yet here he is eight years on. Last year his time really did appear to be up: his form had dropped and although he recovered by May he still hadn’t renewed his contract, while negotiations with Barcelona all-too-publicly collapsed.

There were discussions with other clubs and accusations that he did not care, that he was selfish or unprofessional. Few fought for him to stay. Except those that knew: his manager and team-mates. “It would be difficult to find another like him,” Messi said.

A press conference days before the Copa del Rey final ended with him literally singing “it’s time to go, bye bye.” But two weeks later, after the season’s close, Barcelona renewed his contract.

They did so almost in spite of themselves but with good reason: Messi was right. All season they’d doubted but Alves ended it with three more winners’ medals. And even the summer signing of Aleix Vidal hasn’t ushered him to the door since: when Barcelona faced Arsenal and won 2-0 at the Emirates, Alves started.

“If I had to choose [which medals mean most], I’d say last year’s because there were so many doubts: if I was finished, if Barcelona should get rid of me, if I shouldn’t be there ...” Alves admits. “I wouldn’t say it got to me but it annoyed me because I love my profession, I live for football, for my team, my team-mates. If I only thought about myself, I’d be no use. I don’t want to talk about me, me, me ... and find we haven’t won anything. That’s a disaster.”

There’s something in that response that challenges facile, superficial assumptions. Alves may appear frivolous, but he is not; he may appear daft, but he’s certainly not that either. He may not always conform, but he is a team-mates’ team-mate. Focus may be turned overwhelmingly towards his failings – he thinks so anyway – but he has a habit of winning. And when it comes to the old chestnut, the recurring accusation that even his supporters assume to be true, he has an answer there too.

Assists are fine, it’s one thing setting a record for the most touches in a game as he did earlier this season, but Dani Alves is a defender and Dani Alves can’t defend – even if he did make more tackles than anyone else last season. Or so they say. As for Alves, he says this: “What is ‘defend’?”

“What is ‘defend’?,” he continues. “That no one ever dribbles or attacks? Bloody hell, football would be boring, wouldn’t it? You can prepare [only] to defend but then the guy dribbles past you anyway ... what, you think you’re the only one that’s quick? If you ‘defend’, you don’t attack; if you ‘attack’, you don’t defend? What’s football for? To win. And to win you have to score more. The winner isn’t [just] the team that defends incredibly; if you defend well but don’t score, it’s worthless.”

Dani Alves, seen here tackling Lionel Messi in 2003, told his manager at Sevilla, Joaquín Caparrós, that football has ‘no limits, no rules’ after being asked to stay in his own half. Photograph: Denis Doyle/Getty Images

His is a philosophy that fit with Barcelona’s and one he ended up imposing on Sevilla, so good was he. Alves recalls his early days at the Sánchez Pizjuán where coach Joaquín Caparrós tried to pull him into line before accepting that he was better out of line. “The full-back couldn’t go beyond halfway. I said: ‘Why not?’,” he remembers. “Football is defend-attack, defend-attack ... or attack-defend, attack-defend. Football has no limits, no rules. [Caparrós] changed my position [to midfielder] until he realised that although I had offensive qualities I could do both.”

“If you do the same as all the rest, you’re the same as all the rest: I don’t want to be just another player,” he says. “Then Barcelona signed me. When you sign a player, you know what his qualities are. And what his defects are. ‘He can’t defend’? We’re always looking at things under the microscope, searching for the defect. But if Claudio Bravo gets the award [for the goalkeeper who has conceded the fewest goals], part of that is mine. A tiny part, but it’s there. If you don’t let in goals, it’s because we’ve all done a good job.

“Or look at the galas: Messi has five Ballon d’Ors. I have five [Fifa/FIFPro World XI inclusions]. I always tell him: ‘hey, every time I go, you win!’ Ha ha ha!”

“So, so, so, much criticism makes you reflect,” Alves continues. It’s a theme to which he returns often: the microscope, the criticism, the reflection. So, invited to reflect, what does he think? He smiles. “I think: bloody hell, without defending well, without attacking well, without being able to deliver a decent cross, I’ve been here nine years. Imagine if I’d been any good. I’d be the hostia !” The hostia is the holy host, the consecrated bread. The business, in other words.

Dani Alves’s Barcelona face Arsenal at Camp Nou in the Champions League on Wednesday, having won the first last-16 leg 2-0 at the Emirates. Photograph: Manel Chico/The Guardian

“Write a list of players who’ve been here and how long they lasted; it’s that easy,” Alves insists, one example of course being Alexis Sánchez, whom he faces on Wednesday. “Players come and go. That doesn’t mean they’re bad; they’re beasts but at Barcelona it’s not enough to be beasts. With all those defects, bad as I am, I’m the foreigner with the second most Barcelona games ever. Only Leo’s above me. I think: ‘if I’ve played all of that, I can’t only have defects, I must have some qualities too.’ I know people don’t talk about that, I know the majority don’t like me, but ...”

It’s a striking phrase, one that suggests a hurt that’s rarely far away. The majority? Really? “Well, maybe not the majority but a huge number, definitely. But I’m ready. Praise? Everyone’s ready to hear nice things. But to hear bad things? See how you react. I’m always under the microscope. They forget that under the microscope, a person’s good things are magnified too...”

Alves opens his arms wide: “So my balls are this big!”

“One day I’ll think: ‘I really was different in football’. People think I’m mad, that I say things for the sake of it, that it’s all nonsense, crazy. But, no, it’s not: I think about it. When the consequences come, I’m ready. I just carry on.”

Just carry on? The evidence suggests the opposite, that criticism gets to him.

“Yes,” he concedes. You don’t just ignore it?” It’s not, as people think, that you don’t care? “Noooo ...” he says. “I try to improve; people don’t believe me but I do. I use criticism for that: what would become of me without it? If people only praised me, it would debilitate me. I laugh at some of it but I take note too. You can think criticism meaningless but there comes a point when there must be something there, and that makes you think.

“What is true is that I won’t change my philosophy, because I’d become bitter. If you live your life by what others say, it stops being your life. I enjoy life and the thing I treasure the most is: I don’t hurt anybody. I know people can feel offended sometimes, but I’m not trying to hurt anyone. That’s never my intention. There’s no maliciousness. I want people to reflect.”

“So,” Alves continues without pause, “when I said the press was ‘rubbish’, for example, I did so because they’re damaging football ... And I then came out and explained it [better], because I know there are good people in the profession and it’s not fair to generalise. I can’t stop people thinking I’m a gilipollas [dickhead] or that I just said it to piss everyone off. But, no. I do things like that because I want people to see the damage, to think. Understand why.”

Dani Alves celebrating with his team-mate Neymar after yet another Barcelona goal, this time in the Champions League against Paris St-Germain. Photograph: Manu Fernandez/AP

For Alves, this goes beyond football; asked if he sees himself fulfilling a social role, he doesn’t hesitate. “Yes,” he says. “When I talk about energy, happiness, joy, that’s applicable to life. I try to make people take that on; I hope to be contagious. Don’t be bitter: the world’s already bitter enough, it’s already self-destructing. I want that positive energy to reach people.

“I can’t sing, but I sing. There’s a phrase: quien canta, sus males espanta [he who sings sings his troubles away]. So, I sing. Because I like to, because I don’t like to be surrounded by shit. I like happiness and when people try to destroy that, it winds me up.

“People think the life I lead, being well paid, is the reason I’m like this. No. I was happier when I lived in the countryside with my dad than I often am now. Why? Because I didn’t know how prostituted the world is.”

Alves says he takes mental refuge in Juazeiro, the small town where he grew up, and in his father’s attitude – even if it was one he didn’t entirely share. “I imagine myself there,” he says. “Now, everyone’s on their phone, no one talks to anyone, they’re all looking down [at social media], seeing what others are saying about them. [But] the more you know the world today, the more it disappoints. I don’t understand why everyone fights for power, money, fame. Has no one stopped to think that fame is shit? That the more money you have, the more problems?

“Everyone wants, wants, wants ... and when they have, they feel desperate. Money’s a necessary evil, there to give you moments. It gives me things I couldn’t have, nice things, but happiness? That’s a not a question of money and fame. Quite the opposite. If you’re famous, people are there: ‘Look, look, the famous guy.’”

Alves is flying now. “People talk about famous people and normal people. ‘Normal’? Can’t we all be normal?” he says. “I play football, you’re a journalist, you’re a photographer, but we’re all people. Yet there are labels: famous, normal, rich, poor ... for me ‘rich’ isn’t having lots of money; rich is having loads of things in your head.”

Things like Arsenal? It’s time to get back to the football; there’s a game to talk about, after all. Alves smiles, a little apologetically. “Sure,” he says. So, it’s all over, then? Barcelona are in the next round. “No, no,” Alves insists, “because football teaches you a lot; it knocks you back if you think it’s done. [The tie] looks good, but we have to keep this level. We knew it would be hard but that we’d have chances and we managed the game: when to control, when to attack, when to counter.”

Alves particularly enjoyed the first leg; he always does when England calls. The enthusiasm is clear. “It’s special: there’s a corner and it’s like it’s a goal,” he says. “I’ve always said that playing in England is something I’ve got pending. I don’t know when but I’d like to play there, to experience in person what I see from the sofa. The way the people live football. Wow, it’s incredible. Full stadiums, living every moment.”

Dani Alves says he sings because he likes to sing. ‘I like happiness and when people try to destroy that, it winds me up,’ he says. Photograph: Albert Gea/Reuters

“If you’ve left your skin on the pitch, [English] fans respect that,” Alves continues. It’s an idea he shares. “When you become a supporter, you don’t support them when they win and then not when they don’t. What’s that? That’s no way to understand football. If I’m a fan, I’m a fan always. In England that’s the way. If they don’t win: ‘Next time!’. Not: ‘this lot are shit’. What? It’s easy to sit on your sofa and say: ‘he’s useless’. Go on, see if you can do the same.”

England attracts, all right. So, if Pep Guardiola calls again? Alves bursts out laughing. “Ha ha ha! I don’t think he’d call me.”

Whatever happens, first the focus is here. On chasing a third treble, a second in a row, on more medals. Barcelona have an eight-point advantage in the league, a place in the Copa del Rey final, and the 2-0 lead they take into Wednesdaynight.

“This team lives to compete for everything,” Alves says. It is what he says he has lived for over eight years at the Camp Nou, and before that, but for how much longer? And what next? By May he will be 33 and he admits he’s already thinking about life after football, which will be a life away from football: “Restaurants, fashion …” Not coaching? “No, no.”

“But I do want to do something,” Alves says. “My only concern is, in some small way, leaving a legacy for kids, giving something back. I don’t know how but maybe I can show them that if you want something you have to fight for it, that your energy can carry you. Maybe there’s a way of telling the curious story of the boy who left behind a life where he had nothing, nothing at all, in a tiny town that’s not even on most maps, and ended up at the best club in the history of football.”

The story’s curious, but not yet complete. Outside Dani Alves’s car is parked, waiting; it’s bright orange and it’s time to go. The conversation started with Cafu; it ends with him too. Cafu went on until 35. Could Alves do the same?

“Every time I win something I think ‘you’re doing OK’. I never imagined this but nor did I aspire to be just another person, like my dad did. I dreamed of being someone in football history. That’s why I look after myself, fight, love football as I do,” Alves says. “The only thing I don’t want is for football to retire me; I decide. One day: ‘that’s it.’ Don’t expect [reports] saying: ‘Dani announces this will be his last season’. No.”

So tomorrow, suddenly, you’ll be gone … “What’s the rush?!” Alves protests. “I’m not in a hurry. But I’m not one to think: ‘I’ve got to keep going’. I don’t want football to say: ‘thanks, Dani, but you’re no use any more’. No, no. When I go, I’ll go, saying: ‘thanks very much for everything, football: thanks for the opportunity and thanks for the incredible journey we’ve been on together’.”