I haven’t had any serious arguments with my family but there have been a few moments. I remember being face to face with my father, fist clenched. He was really upset about something I was doing. And he said, “Don’t hit me, you’re going to regret it.” So yes, there were difficult times but I think that goes for all teenagers. In general, we have always been a loving and supportive family.

My parents never had a problem with me trying to be an actor. In fact, they were relieved because I had already done so many shitty jobs. They could see acting was something I enjoyed and was pretty decent. I had done a little in school; I remember a show that was a mix of different songs and dramatic scenes. I played a scene from Murder in the Red Barn, which is a very old piece I think. I had a huge handlebar mustache, which I really liked to twirl. I remember making the theater teachers laugh when we were rehearsing the scene and it gave me a little chill.

I know a lot of actors tell this kind of story, about that first moment when you realize that you can affect someone emotionally, whether it’s their laughter or their tears.. And at that age, it’s usually laughter because you don’t have the emotional depth to make someone cry in a pinch when you’re 13.

My transition to acting came unexpectedly around the age of 21. At that time, I had moved into the planning department because I had been in libraries for five years and wanted a change. Two of the guys who were planners in the office were members of an amateur theater company called Leith Theater and it’s thanks to them that I’m here. They recognized that all the staggering around the office was actually frustration of not being on stage and they thought, we can exploit that. So they said, come see what you think.

I did four shows with this group in a few years – my first role was the rear of a pantomime cow – and I loved it. It was as if someone had let me down. All this farting for years making silly faces and doing different voices – suddenly I was having fun doing the same thing on a stage, and then someone mentioned acting school. I had never thought of it as a job – it was something someone else was doing elsewhere. But I looked and found out you could audition for acting school. So I did, and entered the RSAMD [now The Conservatoire] in Glasgow.

I made the decision after the birth of my daughter to try to have some TV on my CV. Shetland was the very first thing I did on TV after being in theater for 10 years. But the big change in my career was the second set of Course of action. It was a pretty standout TV moment. I remember someone sent me a picture of the front page of The temperature and there was a picture of me and Keeley [Hawes] next to where it says The temperature and I went, damn, that’s pretty big. It was such a great show. And Jed [Mercurio, show creator] had really found its feet with this series, adding the long interview scenes, including some in which I was able to participate. So suddenly I was on this show that everyone was talking about.

And Disaster was the other. Again, it was a fantastic character, brilliantly written and something I hadn’t done a lot, which was comedy. I knew I wanted to do it and I knew I could do it. But Rob and Sharon [writers Rob Delaney and Sharon Horgan] gave me the chance and trusted me. Again, this turned out to be a show that people talked about a lot and are still mentioned to me to this day.

I am not often recognized at the supermarket. Do you know what is going on? People come up to me and say, “Mark! Hi how are you? You’re at John’s school, aren’t you? And I say, “No, I don’t think so.” Then it’s “Oh, I must know you from the bike shop then.” So I say, “Yeah, that’s probably what it is.”

If I could give my youngster one piece of advice, I would say: keep your teeth clean. Submit your statement on time. And don’t worry so much; I have always been worried. I have no regrets because I always look forward, not back, but when I watch myself on TV, I always wish I could start over. Usually I wake up in a cold sweat three months after I finished thinking, I should have done like this, it would have been much better. But I wouldn’t change anything in my life. It’s the past that brought me here, and I wouldn’t change a single sausage.

If I could have one last conversation with anyone, it would be my grandmother. She was adorable and she was very funny. She did yoga. She kept her fags in a big soft handbag. She was fun and carefree. She was the antithesis of my grandfather, who had been in India in the army during the war – he had big chops and was quite tough. She was the complete opposite of him. She died before I was an actor, and I think she would have been completely beside herself to witness all of this. She knew I was in drama college and kind of an actor, but we all know anything can happen to people after drama college. She hasn’t seen anything of my career. I wish she had seen me on TV.

If I could go back and relive moments in my life, it would definitely be the birth of my two children. It was the best, most amazing thing I’ve ever seen. Also the hardest – not for me, obviously, for my wife. But it’s hard to watch your wife go through this. And these were quite difficult deliveries, the two babies were back to back, so it was agony. We started in the hypnotic delivery room with our first baby, but very quickly realized that things weren’t moving forward so we were transported to the ward. But that moment of holding your child for the very first time, and looking at him and having him look at you, is unlike anything I’ve felt in my entire life. I’m crying now just thinking about it. So I’d like to come back to that – not the 36 hours of work – but that time. And slow it down to half please.

Mark Bonnar stars in Litvinenko, airing on ITVX from December 15.

This article is from The Big Issue magazine, which exists to give homeless, long-term unemployed and marginalized people the opportunity to earn an income.To support our work, buy a copy! If you can’t reach your local supplieryou can always click HERE to subscribe to The Big Issue today or give a gift subscription to a friend or family member. You can also purchase single issues from The big problem shop or The Big Issue app, available now on the App store Where google play.

The new book Letter to My Younger Self: Inspirational Women is now available, you can order it here.