It’s a rare thing indeed for an actor to speak candidly about himself, let alone his ambition. Working with the greats, choosing important projects – this is the type of meaningless platitude that is most often served up to a reporter. While Mr Brett Gelman, hero of Stranger Things, antihero of Fleabag, does allow the words “my craft” to tumble from his lips a few times, he manages to discuss such things without coming across as an out-of-touch narcissist. No, he’s very much an in-touch narcissist.

“There’s something inherently narcissistic in what actors do,” he says between chomps of a cheeseburger in a north London pub. “If you’re truly diving into a life of art, there’s something insane about you.”

Earlier in the day, a crew of about 15 Londoners looked on as Gelman riffed and hammed his way through the filming of MR PORTER’s 2022 Holiday short. Provided with a set of prompts and a loose narrative framework, Gelman went for it, ad-libbing (and ad-rapping) until the resulting product was hilarious and something completely of his own making. Sure, we nipped here, tucked there, (and yes there was that talented crew making it all happen), but Gelman’s game performance carried the day. With the ability to conjure a deranged smile onto his face with a flick of the fingers, and freestyle rap about gifts for five minutes straight, he is an unlikely seductor in a 1970s-inspired leather suit.

Now Gelman is ready to talk about himself, his process and his place in the industry. He doesn’t order a beer (“my body doesn’t like alcohol”), but chows down on pub food with sloppy abandon. (“I’m sorry, am I being really disgusting?”)

He is polite and attentive and, seemingly, happy to be here – which isn’t always the case for celebrities who are not being taped for a television interview. It’s not uncommon, for example, to interview an actor who seems determined to conceal every interesting thing about themselves in the name of privacy – a practice that (public service announcement!) tends to lead to boring conversations and, therefore, boring profiles.

But Gelman is here to have a good time, without any of that tiresome industry guff. “A lot of actors sometimes think that reporters and photographers are just showing up to annoy you,” he says. But he relishes the attention. “I love being annoyed! And I deserve it because I’m the most annoying human being on the face of the Earth.”

The 46-year-old Illinois native isn’t what you would call a Hollywood heartthrob – for the most part he plays grumps (Lemon), alcoholics (Fleabag) and conspiracy theorists (Stranger Things). “I think I get cast in those types of roles because they know that I am going to bring humanity to it and because I can, unfortunately, relate.”

His Adult Swim series from 2015, Dinner With Friends, is a perfect encapsulation of his ability to blend acute discomfort with cringeworthy relatability. Even when he is “torturing” his famous dinner guests, his desperate showbiz try-hard host character (also called Brett Gelman) has a smack of truth to it.

He’s clear-minded about his niche in Hollywood (damaged, weird characters) and his place in the world as a white man. “You hear this bullshit that we’re not interested in seeing despicable [male characters] anymore,” he says. “Well, what do you want to see? Perfect men? We are despicable. We damaged society! Shouldn’t people be reminded of that?

“I am a misfit and a weirdo and I’m proud of that,” he continues. “I think that the misfits and weirdos are the ones who see the truth and other people are living with a veil over their eyes. Sometimes, seeing the truth will break you, it will drive you to become an alcoholic or to lock yourself away in a bunker. We’re all teetering on total madness.”

Gelman is in therapy, which is perhaps why he’s able to speak so fluently about madness, fragility and narcissism. “Oh yeah, [therapy was] desperately needed,” he says. “Therapy is like exercise: it’s a lifelong practice to keep you healthy.”

Earlier, we had spoken about Mr Kanye West and his antisemitism (our interview took place in October, before West’s more recent outbursts), and Gelman, who is Jewish, expressed his hope that West gets the help that he so clearly requires. “We’re really seeing the effects of neglect in mental health,” Gelman says. “I’m not saying that people have gotten crazier, we just see people’s lives more and I think the silver lining is that you can get therapy.”

Like any good man working on himself, Gelman wants to evolve, he wants to move forward. “I’m pushing towards being seen more as a leading man, being seen as someone that one wants to have sex with – or marry!” He seems to be manifesting this in real life: he’s been dating the pop-singer Ms Ari Dayan for the past four years (and was married to the director Ms Janicza Bravo before that), so clearly someone wants to have sex with him. Gelman is upbeat and ambitious about moving his way up to the top of the call sheet, believing that it’s both possible and inevitable. He has a theory, though, as to why it hasn’t happened quite yet.

“I wonder if it’s antisemitism sometimes,” he says. “That people see me do a flawed character and they’re like, yuck, I love him, but yuck. They might see someone else do that and think, they’re so complicated.” He can list Jewish actors that have come before that were considered sex idols, but they’re all, notably and surprisingly, of an earlier generation.

He names Mr Dustin Hoffman (“you don’t get much more Jewish than that”) alongside non-Jewish actors such as Messrs Gene Hackman and Robert Duvall as figures who were able to break through as leading men despite, well, not looking like Mr Robert Redford. “That was sort of the beauty of the 1970s: [Robert] De Niro and [Al] Pacino. Even though they weren’t Jews.”

Mr Adam Sandler, he says, has “most certainly” achieved leading-man status since. But back in the 1970s, the industry was rougher around the edges, not as dedicated to leading men who weren’t necessarily visual perfection. Men were furrier and less chiselled, their faces had character. For this reason, perhaps, Gelman suggests, it would have been easier for him to have been seen as a sexual being. “I think that [in the 1970s] Hollywood opened up to what more people’s tastes were. Not everybody wants a Chris.”

Gelman is certainly not a Chris (“no shade on them”). Like the characters in his film and TV projects, he sports a shaggy beard and a thinning hairline with a wispy combover. He’s imposingly tall and emphasises his presence with a wild fashion sense. On the day of the shoot, he’s wearing an array of Japanese brands, but when he’s on the press trail, he favours brands such as CELINE HOMME, BODE and Gucci. Big prints and bright colours on a big man with an even bigger personality – it’s a lot to take in.

“My publicist said I was like an old-school movie star and I really dug that because I think I bring a certain 1970s aesthetic,” he says. He credits a head-to-toe CELINE HOMME look worn during a July appearance on The Late Show With Stephen Colbert as a “eureka moment” for him. “The BODE moments and then that – it took it to a whole new level where I felt I found my identity in a way that I never had before.”

The public seem to be reacting quite positively to this identity, throwing open the possibility that Gelman can indeed achieve the leading-man level roles he desires. “I’m doing something that no other actor like me is doing,” he says. He’s drawing from things he’s passionate about like outré fashion, 1990s hip-hop culture and his Jewish heritage to craft an utterly singular, sometimes abrasive, but always massive and magnetic presence. “It’s sort of a process, but it’s also something of a slow burn,” he says of his evolving relationship to fashion and, by extension, his career and his fans.

A middle-aged man constantly on the cusp of breaking through but not quite enjoying top billing (yet), could easily be jaded and bitter – maybe even a little manic, like the characters. But Gelman appears genuinely to be choosing joy instead. “There are a lot of things I’m proud of that I did before Fleabag and Lemon that people dismissed,” he says. “[Now that I’m successful], people will go back and look at Lemon or my Adult Swim Dinner specials and take that in in a new way, in not so much of a judgmental way because now they know me.”

He grins and licks his fingers between fries, the mischievous Gelman rising to the surface. “And it won’t just be that they’re watching total mental illness happening on screen.”