Months before Ovie Soko applied to be a contestant on hit reality show Love Island, he set himself a goal. “I’m a huge believer in manifesting stuff. You know – that if I write it down it will happen,” the 29-year-old says. “So I wrote in my journal: ‘Provide a service or a product that helps people feel better about themselves and it will reach millions of people.’ I hadn’t a clue how I was going to do that. So to go on to Love Island later and get that reception, well, it was nuts. Blew me away. Still does. I don’t really get it but nonetheless, I do appreciate it.”

Previously only known to basketball fans (at the time he was signed to Spain’s CB Murcia), Soko was instantly catapulted to fame. Almost overnight, he earned millions of fans who were struck by his self-possession and chilled personality in an environment where bravado and insecurities reign supreme. He became known for his wise words of comfort and advice to the other contestants, including pulling other men up on any disrespectful behaviour toward the women on the show (and there was a lot). It is in this vein that his debut book You Are Dope (subtitled “Let the power of positive energy into your life”) continues, offering guidance, advice, and inspiration on how to become the “dopest” person you can be.

So what is dopeness? “Dopeness is innate, and it’s in everyone,” reads the book. “You’ve probably been dope for a lot of your life and didn’t even realise it. Remember the time you did the washing-up for your mum and dad without them even asking? Dope.” Broadly speaking, dopeness is a feeling of contentment, self-awareness and self-acceptance that isn’t reliant on money or social status.

“When my management first said publishers were interested in me writing a book, I thought ‘of course not, I’m not an author’,” says Soko, who co-wrote the book with Guardian journalist Lanre Bakare. “But maybe people took a liking to me because they saw me as being a bit different on the reality TV setting. And I just think ‘hold on, all you guys are different, too!’ Everyone’s different. And that’s something that should be celebrated, not just because someone’s on reality TV. You should celebrate yourself, not what is sold on Instagram.”

For Soko, helping others be “grateful and happy” through the book is his way of giving back to the many people who have been “so warm” toward him since his appearance on the show, and is a particularly personal undertaking as an avid reader of self-help books himself (he says they “helped me advance my life.”). His book is similarly bright and accessible, coming with worksheets to help readers organise their thoughts, and packed with anecdotes from Soko’s own life. Learning to overcome doubt through professional basketball, dealing with social media pressures after Love Island, or navigating two cultures, as a young man raised by Nigerian parents in London – but it’s not a memoir, he insists.

“I’m not going to write a memoir, I haven’t lived long enough,” he says. “The book has stories about me, and lets people into my life, but the goal is to show people how I dealt with certain situations. There’s lots from my life that isn’t in the book.”

Soko joins a roster of personalities – Fearne Cotton, Russell Brand and Chidera Eggerue to name a few – who have entered the self-help space, a genre that has seen sales boom by 20% to reach £30m a year. The book is not explicitly written for men (“I think men and women can benefit from this material,” says Soko) but with chapters on masculinity, and the lessons he’s learned from his romantic relationships with women, You Are Dope will have a very strong appeal to men, especially young men.

Self-help books for young men have come under scrutiny in recent years as some of its most popular authors are accused of repackaging alt-right ideologies and misogynistic thinking in the guise of self-improvement. Perhaps the most famous example is Jordan Peterson, the Canadian psychology professor who ostensibly gives out tough love to disaffected young men, but whose classically influenced philosophy champions strict social hierarchies, including along gender lines.

Against this, Soko’s book is a breath of fresh air. He describes a masculinity that can be soft, and urges the reader – especially young black men – to resist social pressures. And instead of laying out a sweeping philosophy to inform a fixed code of conduct or way to live, he urges the reader to use their own inner compass to figure out what is right – or what is dope – for them. In many respects it’s a progressive answer to the demand for men’s self-help, but without ever using the word “feminism”. Would that have been a step too far? Or was he simply playing it safe?

“I think it takes more guts to live by your own internal compass than to live within the safety of what everyone else thinks,” says Soko, who argues that the personal growth he wants to help his readers experience can be hindered by labels. “In politics, everyone wants you to take a side. But if you think about what you actually believe in, you’ll probably not fit fully into any one specific political group. Maybe you agree with most of it so you put yourself in that box, because we’re trained to think that if you don’t fit in a box, you’re weird.

“But hold on – it’s a bit weird that you want to be put in a box. Everything about our lives since we were born, systematically as a society, is to train us to believe that you must fit inside the box. Your house is a box. We drive in a metal box. We go to school and sit at square tables. Well – how about you think outside of the box?” he exclaims. “We’ve all been given the mind that enables us to, but the older we get, the more we get used to just trying to fit into the parameters created by those who run the society – which is obviously a tool used to control the masses – and the more we feel alienated by our own intuition. Our own intuition becomes foreign to us, and it becomes madness. Don’t do that to yourself! You’re selling yourself short.”

Does Soko think he’s now living to his full potential? In addition to writing a book, earlier this year he became the face of Diet Coke and finished filming a new BBC documentary exploring life after reality TV. He has also launched a fashion line for Asos, all while continuing to play professional basketball in France.

“I do have goals. I want to do stuff in fashion, and maybe do some more TV. So I’ll just keep on knocking down little milestones,” he says. “But the overall goal, the main goal of my life is to be happy and give back. Help other people be happy. And if you ask me, that’s a life well lived.”

• You Are Dope by Ovie Soko is published by Quadrille Publishing.