It’s just natural that I will distance myself from The Inbetweeners
The screenplay was actually written by Simon’s wife, author Lisa Owens (the pair married in 2012, having met at Cambridge University, and have two young children together).
“It was an amazingly smooth process actually, and we’re still happily married!” he jokes.
When it comes to his previous directing work in 2016, Simon made a short film – Ernestine & Kit, a darkly comic fairy tale about two elderly ladies who imagine all manner of immoral goings on as they drive across Ireland.
But he admits he felt he had to prove himself throughout the process of making Days of the Bagnold Summer.
Trying to get funding for the film was “the most stressful and difficult process”, he continues. “Actually, being on set and all that stuff came weirdly naturally and I felt quite comfortable doing it. I didn’t feel comfortable raising the money.
“And you slightly have to fake it until you make it, you have to convince people that the film is going to be really successful and make loads of money when in your heart of hearts you’ve got no idea that that’s the case, or don’t really believe it.”
Simon knows that Will McKenzie – his character in The Inbetweeners, which ran from 2008 to 2010, followed by two films in 2011 and 2014 – is a part he will be asked about forever.
The Channel 4 sitcom, which followed the escapades of four hapless school friends, had a huge fanbase, and has cemented itself as a national-treasure sitcom.
Was there a part of him that thought turning to directing would be an effective way of taking control over how people see him?
“I guess so,” he muses, thoughtfully.
“Maybe that is on a subconscious level. I never thought of it as, ‘What can I do to distance myself from The Inbetweeners?’, because I knew it was something I wanted to do.
“It’s natural that I will distance myself from The Inbetweeners, because that’s not my thing; I didn’t write it, it’s just an acting job I did for a few weeks every year.
“Despite that, I think for my first project I have chosen something which unfortunately does have quite a lot of similarities to The Inbetweeners, in that it’s contemporary and suburban and there’s a teenager in it.
“But that was not deliberate... this was the story that most jumped out at me for whatever reason.”
Simon recalls how seeing The Inbetweeners creators Iain Morris and Damon Beesley – who also produced the show – directing The Inbetweeners films made him realise he could have a go at directing.
“They are just such normal people,” he says. “When they started doing it they were in their early 30s, so I was like, ‘Oh right, it’s not some super skill that you need to have done years of training for, it’s sort of doable’.
“And, if you surround yourself with good people who do the technical stuff and you have a clear vision of what you want to do, it’s possible.”
He says the casting directors for Days of the Bagnold Summer really pulled it out the bag with Brightonborn Earl, who is only 20 and is the son of Australian singer-songwriter Nick Cave.
“I’d never heard of him or seen any of his stuff and that was obviously the part that we were most worried about,” he admits.
“We saw lots of kids and a lot of them were amazing, but a lot of them were doing the classic grumpy Kevin and Perry Go Large teenager thing, whereas someone like Earl, he does that, but you can see underneath he’s really sweet and nice, as he is in real life.
“So, I hope that’s there in the film, even though he’s quite narky with his mum it’s clearly just a phase, and you can see Daniel has a sense of humour.”
Simon would love to do more directing work in the future, calling it “really fulfilling”.
“I’d like to still be an actor as well because I love acting and in an ideal world, I’d be able to do both things in parallel,” he says.
“I was about to say that’s the plan but really there is no plan... We’ll see what happens.”
But as for directing himself in something?
“I can’t see myself doing that. I think I’d just be paranoid, anxiety about that whole thing.”
Back to his acting work, and earlier this year, the sixth series of Friday Night Dinner reached huge audiences – its biggest yet.
With the first series having aired in 2011, Simon reveals it’s not a role he expected to do for quite so long.
“I always felt it had that sort of cut-through potential because it is a show about family, and I think anything you can watch with your family has the potential to really hit home with people,” he suggests.
“I’m really glad it has taken off. It only took a decade for that to happen!”