It’s 11am, which means Gaten Matarazzo is safe to be outside. “If I’m walking down the street and school’s letting out, I have to not be here very, very quickly,” says the 24-year-old, settling onto a stool in a London hotel bar, “because that can be a little intense.” Evenings can be dangerous, too. “I was at a bar in Milan, and the word had spread. People were like, ‘Hey, everybody, wherever you are, come down now.’” It sounds overwhelming. “It was a little stressful,” he nods. “But it’s so kind of people.”

Matarazzo knows that he is, to most people, Dustin from . He knows that he will possibly always be Dustin from – that in some people’s minds he is preserved in amber as the sweet, geeky kid in a trucker cap who helped save the world from supernatural evil in Netflix’s phenomenally successful TV series. It’s an inevitable side effect of being one of the most famous child stars since .

The child stars of are not children anymore, though. Millie Bobby Brown has a husband and two children. Sadie Sink is a Marvel star. And Matarazzo lives in New York with his long-term girlfriend Elizabeth and their two cats, Joan and Jett. But a year on from the finale – which was watched by more than 100 million people – he is, he admits, struggling to figure out how to not be Dustin.

“There’s like a parasocial thing that people have of knowing you from something specific and then being like, ‘Please don’t do anything else,’” he says. “A lot of times, when I jump into other projects, they’re like, ‘Good for him, but I really can’t see him as anything else.’ And initially, I will admit, that weirdly hurt my feelings. But like, why the f**k would that hurt my feelings? I’m not gonna let that mindset aid in my decision making.”

There’s something immensely likeable about Matarazzo. Taking a break from rehearsals for the new West End production of , he arrived clutching a lurid pink Monster energy drink – “Sorry, this is a bad habit of mine,” he muttered, shoving it in his rucksack – which he has now swapped for a flat white. He’s earnest, enthusiastic, and unnecessarily apologetic – he’s sorry for the energy drink, for talking too much, for not being able to stay for longer than an hour.

So I believe him when he says he’s worried that fans turning up to just to see Dustin from might make his co-stars feel bad. “It would not be a problem for me,” he says, “but I would be upset for the other people in the show.”

He plays Mark in Luke Shepperd’s London revival of the 1996 rock musical, about a group of broke young artists living in New York City during the HIV/Aids crisis. Matarazzo was first introduced to when he was a child working on Broadway – aged 11, pre- fame, he starred as Gavroche in . “There are lots of gay men in musical theatre,” says Matarazzo, “so as I was growing up, I was in spaces and rooms where these conversations about the Aids crisis were coming up.”

He didn’t know what it meant – so he did what most 11 year olds would do, and asked his mum. “She didn’t really know how to articulate it,” he says, “and one of the ways that she introduced it to me was through .”

Matarazzo’s character Mark, who serves as a sort of fourth wall-breaking observer, is a straight man whose friends are mostly marginalised outsiders, some of them dying of Aids-related illnesses. Has Matarazzo spoken to anyone who’s experienced something like that?

He hesitates. “My uncle was a closeted gay man in the 80s in New York,” he says. “I guess most gay men were publicly closeted, but he was open to his family. He’s now 81, and when I ask him questions about New York and gay culture in the 80s and what that looked like, he really does love to talk about the joy of it, and I find that beautiful. I couldn’t even imagine the fear that persisted throughout his thirties and forties. That must have been very, very scary.”

In many ways, then, Matarazzo has been preparing to play this role for most of his life. But has there been any backlash, from people who don’t know he’s a seasoned musical theatre actor and think he was only cast for his fame? “For sure,” he says, “but that a factor in why I’m cast in things. To deny that would be silly and misguided.”

As for the idea of people turning up solely to see “Dustin”, “that’s a very kind thing for them to do”, he insists. “But sometimes people show up in costume. It comes from a place of love and admiration” – he pauses, corrects himself – “I won’t say love. It comes from a place of admiration and appreciation. But there are 20 other people on the stage. It would be inappropriate of me to say if you’re coming because of , don’t come. But I think I feel comfortable saying don’t come in costume.”

I ask why he just retracted his use of the word “love”. “I think it’s important to make a distinction between admiration and love,” he says, “because there is a weird little world where people who are very, very invested in develop an intense attachment…”

That attachment was encouraged by the studio early on. When started, Matarazzo’s Instagram was full of candid posts about his friends and family. “I remember people telling me it was very important to have a public display of who you are as a person, and taking on the responsibility of that at a very, very young age. It took me a while to realise that that’s not an obligation that I necessarily need to do, nor is it one that I think is healthy for a child to do. I was 13. I do wish that I was able to register that it may be inappropriate to have consistent conversations with strangers online and talk about intimate details about my personal life.

“Like, what do they say to kids growing up about being online? Don’t give away personal information about yourself. Don’t talk to strangers. But it almost seemed like when there was an incentive for other people involved…” He trails off, reluctant, I suspect, not to seem ungrateful to the people who gave him his career.

Nowadays, having deleted all posts pre–2021, Matarazzo has a drastically different relationship with social media. “My account is fairly active, but I’m actually not even logged into it personally,” he says. He has other people do it for him. It might disappoint his 19 million followers, but it’s made him much happier. “I just developed an anxiety around it, and don’t really desire pushing private details about my life that I don’t feel comfortable sharing.”

In March, he didn’t do a post to celebrate his eighth anniversary with his girlfriend. “And people were like, ‘Oh my god, they’re not together anymore.’” He laughs. “We’re very much happy and healthy and very communicative.”

Does he feel, given the pressure he was put under to share his life on social media, that he was exploited as a child? “No, because I was surrounded with really good people,” he assures me. “I hear about child actors at other studios now who get put through the f**king ringer, and we weren’t. At least, I wasn’t.”

He is adamant, too, that there was nothing exploitative about the Duffer Brothers – the creators of , whom he describes as “good dudes” – writing his medical condition into the show. He has cleidocranial dysplasia (CCD), a one-in-a-million condition that affects bone growth. Many of the things that endeared him to viewers in the early seasons – his small frame, his lisp, that goofy, toothless smile – were because of his CCD.

“They saw how open I was about discussing it and showing people my shoulder trick” – where he touches his shoulders together in front of him, a talent courtesy of having no collarbone – “and my teeth” – he was born with 14 extra baby teeth, which eventually had to be removed, and his adult teeth manually pulled down – “and they met me at my level”. “They were like, ‘We know you’ve experienced some bullying. These characters are consistently bullied. How would it make you feel if we have these things be a source of that?’ It was just like, ‘Yeah. That makes sense.’ And their intention wasn’t to elevate that or give it a voice. Inadvertently, it’s what it did.”

Is he proud of that? “Oh my god, of course I am.” There’s a community of people with CCD now, which means it’s easier for him and others to compare symptoms. “My knees are way more f**ked than they were even five years ago, and at 24, that’s concerning to me. I don’t want a knee replacement when I’m 30. Who knows what that looks like. I’m like, ‘My knees hurt. Is that CCD or is that just my unathletic ass?’ Nope. All of our knees hurt. Let’s figure out why.”

All in all then, Matarazzo seems to feel that he’s had it pretty good. He certainly seems to have avoided the many dark, dangerous and sometimes deadly pitfalls of child stardom. “There are still leaps and bounds to be had in ensuring the security of kids in this industry,” he says, “and even questions as to whether it is a place for children at all. A lot of times [your parents] have to stop doing their job, so you end up inadvertently becoming the breadwinner for your family at a very young age, which is complicated. And I’m sure it was equally as weird for my parents to settle into that uncomfortable dynamic.”

It was worth it, though. “That weird dynamic is a sacrifice made to ensure that I got to do something I love. Because every time the proposition of not doing it came up, that was terrifying to me.”

‘Rent’ opens at the Tom Stoppard Theatre, London