WHO are we? No, really. Let’s analyse the notion for a moment.

Actor Martin Quinn suggests we aren’t simply one person.

“We all have so many different sides to our character,” he offers. “We act differently with different people.

“I’m certainly not the same person to my gran as I am with my best mate. We each have different versions of ourselves we reveal at different times.”

Martin is set to star in a role in which he plays a character removed from the man he purports to be.

In Chris Grady’s new play Outside In, which runs at Glasgow’s Oran Mor this week, Martin stars as Coco.

Coco we learn is a bad boy and one day he shoves a threatening gun through a letterbox.

The letterbox belongs to Jay, (Cristian Ortega) who happens to be an agoraphobic, trapped in his house alone. And the gun blows up his quiet universe.

Read more: Fake nose won't get in the way of a very real performance

“What happens is we see these two guys develop a relationship,” says Martin, smiling. “It’s a very unlikely relationship, and what that turns out to be I won’t say, but it illustrates the notion we’re not all whom we seem to be.”

We have an actor playing a character whose character is not as expected? “Yes, and I love that about the play,” he says, smiling.

“I love being able to access a part of me that helps me to play him.”

Which part of Martin was ever an apprentice gangster? He laughs as he explains his route to acting didn’t involve guns at all.

“I grew up in Paisley where I attended Pace Youth Theatre. I loved acting and went on to join Scottish Youth Theatre.”

The experience paid off massively. The teenager landed a role in the National Theatre of Scotland play, Let The Right One In, which was so successful it transferred to London’s West End. (Interestingly, his current stage partner, Cristian Artego, was also in the play.)

So much, so young? Did the then 19 year-old Quinn think he had arrived?

“Probably,” he says, laughing. “I did think the job would be easy. Yet, I came to discover I was terrified when it came to auditions. That first play director figured I was just right for it, we clicked.

“But after that I would be frozen to the spot when going into casting rooms. So I went to drama school in London to try and get over that fear.”

Drama school, he says, taught him how to deal with pressure. “And what made me tick,” he says. He grins; “It was three years of being picked apart in front of your pals.

“But I also learned how to read a script and get an idea of what I want to do with a character. Now, I can go into an audition thinking how I can sell my idea, to be able, as Bryan Cranston says, to offer a set of skills the director can use.”

Casting directors picked up on Martin’s skill set package. He landed a role even before he left drama college when he appeared in the latest Alan Ayckbourn play, The Divide.

Since coming back to Scotland the actor has starred in the classic comedy journey, Passing Places.

Read more: Fake nose won't get in the way of a very real performance

And not surprisingly; his enthusiasm is infectious, and he reveals a real keenness to call upon personal experience.

So what does Martin take from growing up in the Gallowhill housing scheme he can use to form bad boy (on the outside) Coco?

“Well, the most rebellious thing I did was wear an Adidas track suit to school once, but I soon realised it looked ridiculous.

“And when I played for the football team I did get into a scrap. That’s not really me, but there was a part of me that wanted to show that I could be up for a fight.”

He pauses and grins; “I got beaten up and my nose broken. I can’t fight at all. But that experience is very much Coco, trying to act the big man.”

Martin Quinn underlines his non-toughness when he talks of being in London and homesick. “I love home. I really want to work here. The only little problem is my girlfriend, whom I met at drama college, lives in London.”

Which side of his character does he present to his partner? “The sensible side,” he says, grinning.

Outside In, Oran Mor, Glasgow, until Saturday, also features Katie Barnett as PC Kayleigh.