Hello Nick Knowles. How are you?

I’m very well thank you. You sound surprised to hear me.

I’m surprised you rang yourself. There’s normally an intermediary involved.

No no, it’s me. I spent so much money on this film that I can’t afford an intermediary any more.

Hang on, you spent your own money?

I put a lot of my own money into it, yeah, because it’s been a seven-year process from writing the film to actually getting the thing out there. It has been a labour of love and, like all love stories, there’s been a certain degree of pain.

Like what?

Well, it was hard to find anyone who would actually take it seriously. The BBC didn’t want to look at it. FilmFour didn’t want to look at it. Film England didn’t want to look at it. The BFI didn’t want to look at it. None of them treated us seriously, I think, because it’s been written by that bloke off the DIY programme so it obviously can’t be any good. Over seven years, I’ve put tens of thousands of pounds into it.

The premise of the film (1) reminded me a little of Breaking Bad.

In extremis, people just get to the point where they have no choice. This is a story about pensioners who robbed a bank, after the bankers had already robbed their pensions. And then bugger me with the wide end of a jazz man’s trumpet, last year – after six years of making the bloody thing – the Hatton Garden robbery happened, carried out by a bunch of pensioners. But this is a family comedy. You can go and see it with your grandkids and grandparents.

Well, there’s a lot of dildo talk in it (2).

There’s a lot of, um, gentle naughtiness based on the idea that people over 60 are as full of passion as anyone else. We make reference to that. But the truth of the matter is that you don’t stop feeling the things you feel just because you get older.

How did you get such a good cast? (3)

We couldn’t really afford that cast. We secured Virginia McKenna because I wanted an actor that had dropped out of circulation a bit, like Travolta before Pulp Fiction. Then, literally, I was driving to B&Q when I suddenly pulled the car over and said: “Virginia.” She was a massive star in the 60s, but she’s retired. I biked the script to her and the next morning she rang and said: “I love it, it reminds me of the Ealing comedies I used to make with Peter Sellers.”

Are you going to write any films after this?

Oh, I’ve got four more written.

Have you?

Yeah, but they’re all historical ones. One’s set in 16th-century Ireland. Then there’s one set during the French revolution, in London and Paris and St Petersburg. That’s like a massive Anna Karenina movie. The cheapest one is set in Mauritius, and that looks like the one we’re going to go for.

Why are they all set in the past?

It’s difficult to sell a modern-day British film around the world. Although, having said that, the Beijing film festival has taken Golden Years as one of the prime films there. They’re waxing lyrical about it and they love it. We’re also playing Cannes. (4)

Are you going to go?

I can’t go to Cannes. This is how my life goes. I’ll miss Cannes because I’m recording a series of Saturday night quiz shows for BBC1.

If you had to either exclusively write or present, which would it be?

Gah, that’s tough. I mean DIY SOS I’m in love with, because it’s way beyond a TV programme. It’s way beyond a career thing for me now. I don’t mean that arrogantly – it really has become more than the sum of its parts. To get 9 million people watching a programme on a Wednesday about post-traumatic stress is a wonderful thing. So if I had to pick one thing, it would be that. But I love writing. The problem is that my next movie is a £30m film.

Were you tempted to cameo in Golden Years?

I did! During one of the police chases, you can see me walking across one of the streets for about a second and a half. In fact, I was in Room with a View. I was a student, and I went there to work as an extra, and I’m actually on screen more in Room with a View than I am in my own movie (5).

I have a cracked spindle on my bannister and I don’t know how to fix it (6). What should I do?

Why the hell do you think I’d know?

Foot notes

(1) In Golden Years, a group of senior citizens lose their pensions and decide to hold up a string of banks with fake guns and fake bombs. (2) Una Stubbs talks almost exclusively about genitals. (3) The film also features Bernard Hill, Sue Johnston and Simon Callow. (4) The market, not the competition. (5) I have not checked this. (6) If my landlord is reading, I made this up.

• Golden Years is released in UK cinemas on 29 April