Simon Amstell's New Film Helped Him Understand His Twenties

"Why, did you want more sex?" asks Simon Amstell, intrigued, if a little indignant.

It's not that I wanted more sex, I explain, it's just that there's obviously quite a lot of sex going on in his debut feature film – Benjamin – and I didn't get to see very much of it onscreen. I'd quite like to know why, is all.

"You definitely see the beginnings of a lot of sex," he says, going on to describe in some detail a particularly intense kissing scene between the film's title character and his love interest, Noah. "The thing is, a lot of the film is funny, and there's a danger, with a lot of sex, that you end up taking the audience somewhere else, to another genre."

He was concerned, essentially, that in dedicating too much time to full-on sex scenes he'd forget to make people laugh. Which makes sense, really, given how important making people laugh is to Simon Amstell.

We're sitting in a Benugo just off Great Portland Street and Amstell has just ordered a peppermint tea and a water. I had asked him to make brunch with me at London's Cookery School, using all the ingredients I'd purchased for vegan sausages – logical, I figured, given the fact he's a vegan and there's been all that stuff in the news about vegan sausage meat. But after a short conversation with his publicist it was decided that he'd rather not, if that was OK; that it would be better if we just sat down, didn't make sausages and had a chat.

With anyone else I might have felt a little uncomfortable, having had my genius idea rejected, but not with Amstell. He has form when it comes to conducting slightly unconventional interviews, so I feel no shame.

After being fired from children's TV network Nickelodeon for "being too sarcastic" nearly 20 years ago, his six-year stint presenting T4's Popworld alongside Miquita Oliver began. Tonally, interviews with pop stars ranged from subtle ribbing to explicit piss-taking: he asked Britney Spears whether she'd ever licked a battery, Rachel Stevens if she'd ever squashed a squirrel (she hadn't). Amstell is the man who asked the McFly boys if they'd recently fucked each other, who interviewed Fame Academy's Lemar from a distance with a megaphone, in a groundbreaking segment titled "Lemar From Afar". "It was a lot of fun," Amstell remembers. "We were just very silly and naughty all the time, and people really did just seem to like it."

From there, he moved on to Never Mind the Buzzcocks, where his presenting style was blunt, cutting and – while certainly hilarious – sometimes unapologetically mean. An example, as if you need reminding: the time he goaded Ordinary Boy Preston so relentlessly that the singer ended up storming off set. I wonder if the now-mellowed Amstell – who, don't forget, won't even make breakfast with me – thinks it ever went too far.

"I stopped doing it because I thought if I kept doing it then it would start to become very predictable," says Amstell. "Once I know how to do something, I feel bored; I just knew the joy would go out of it."

There's a pause. I point out that this doesn't really answer my question.

"I know," he says. "Hmm, let me get to it. What was it?" A sip of tea, a few seconds of silence. "The intention was to make something incredibly joyful and silly," says Amstell, carefully, "but I think there were moments where the expectations of the format led me to pushing a bit too hard on occasion. It's not the kind of thing I'd be interested in doing now, but when I was 25 it felt very exciting."

I think his answer to my question is something of a yes.

There's no doubt, though, that Amstell's style is what allowed him to make a name for himself – an ambition that drove everything he did from the age of 13 until about 28. "The priority was: make sure as many people know about who I was as possible," he says.

Amstell watched The Big Breakfast religiously, and fostered something of an obsession with Eddie Izzard and Ruby Wax. As a young teenager, when he decided he wanted a career in comedy, his ambition wasn't just to make people laugh, but "to be a funny person on the television". Why? "Both in comedy and the shows I was watching on television, people were celebrated for their peculiarities rather than confined by them," he answers. "There you go – is that what you wanted to hear?"

The thing is: it's not, because that implies the kind of recognition Amstell achieved was somehow incidental – which I don't buy. In everything he's done, he's been the star. His gloriously funny Popworld interviews purposefully became more about him and his questions than his subject. On Buzzcocks, viewers tuned in almost exclusively to see how far Amstell would push his guests that week. Grandma's House – a BBC sitcom created by Amstell and his friend Dan Swimer – is about an awkward gay Jewish boy called Simon; in a Guardian review, Sam Wollaston remarked: "Can Simon act, though? Well, it's hard to know really, given that he's essentially just being himself." Even in Carnage – Amstell's utopian vegan mockumentary – his voiceover makes him ever-present. There has to be a reason he's always placed himself front and centre.

"It might just be a lack of imagination," he jokingly suggests. It's only later on – when we revisit the question – he accepts that his creative output was somewhat driven by a hunger for celebrity. Does he like being famous now, I ask. Was all that effort worth the prize?

"This is a really good question. When I was a kid, I thought fame would solve all my problems. I thought there was no chance of ever being lonely because you would have a load of stuff to read about how much you were loved," he laughs.

For a long time he thought being famous would somehow make him safe. "As soon as I was recognised in the street for the first time and noticed that it didn’t fill me up in the way that I thought it would, I got that the fame aspect isn't anything more than a way of making sure people see the things that you've created," he continues. "After I realised that – and a couple of breakdowns – I really honed in on the things that I really need to express."

Today, his interactions with strangers have become more meaningful: "With the kind of work I do now, it always feels very personal when somebody says something to me. Like my standup show Numb, which was basically – although I didn't know it until I'd finished it – all about depression. When someone comes up to me and tells me they found it helpful, it's really lovely. There's a different quality to my interactions now. It's very fulfilling and it makes me feel useful."

He's also becoming more outspoken on issues that matter to him, like the "necessary transition" the human race will have to make to veganism at some point soon: "It feels like it's just an essential thing which is going to have to happen, else we'll all just die."

He recalls a scene in Carnage where a cow, starring in a musical, sings about her child being taken away so people can steal her milk. "Other than that just being quite a funny scene, it does make you think about cow mothers having their children ripped away from them so that we can drink their milk, which is nothing to do with us," he continues. "That milk is for that calf! Imagine if calves started attaching themselves to human women and then started complaining of lactose intolerance!"

"Sorry if my answers are too long," he blurts out, cutting through the sincerity. "If at any point you're bored please, do feel free to just leave."

By the time we've discussed drugs (legalise them!); having kids (the idea makes him both warm inside and terrified); and his beauty regime (Bumble and bumble hair product, moisturiser, suncream and hats), which has kept him looking a remarkably young 39, I'm told Amstell has another interview to get to, so start asking about the thing he's here to promote.

Writing and directing Benjamin was a form of therapy, says Amstell – although he's quick to add that writing a script shouldn't be considered a substitute for the years of actual therapy he's had. Played by Colin Morgan, Benjamin is a young filmmaker riddled with anxiety about both his professional prowess and social abilities, whose life becomes all the more complex when he accidentally begins to fall in love, his vulnerabilities laid bare.

"I suppose I wrote it as a way of figuring out what was wrong with me in my twenties," Amstell reflects. "I suppose he's me before I got better."

Benjamin starts out depressed and lonely; when the prospect of a meaningful relationship looms, he's quick to push his potential partner away.

"The film is about somebody looking for love from an audience because he's terrified of intimacy," he explains. "When I started writing the film I didn't know that was the character's problem. By the end, I got why it had been so difficult to find and keep meaningful relationships – I wasn't used to being… when Benjamin meets Noah, he's confronted with somebody who is present and able to love him."

Amstell says he can see now that, when he was in his twenties, he wasn't "used to just being loved close up without having to do anything", instead always performing and putting on a show. "I realised in writing this film that this was the problem – this fear of letting somebody get close to you was the reason I was so terribly lonely," he says with a laugh.

I ask if he thinks he'll continue to use his work to explore his own experiences; whether he'll always make it personal. "I think I'll always want to do that. There are moments where I feel confused or scared and need to figure out what's going on, so I'll always end up writing about it," adding that it’s useful to him, and that he hopes it's useful to others. Writing for the sake of writing just doesn't appeal.

"It's so hard to write and direct a film that the idea of doing it without this need to figure out who you are or what's wrong with the world would be boring – boring and difficult," he says. "Why would I do that?"

Benjamin is in cinemas and on digital on the 15th of March.

@MikeSegalov / @christopherbethell