TEN years ago, the teenage Lorn Macdonald had a Trainspotting poster on his wall, featuring the ‘Choose Life’ speech.

‘Choose life. Choose a job. Choose a career. Choose a family. Choose a f****** big television . . . ’

Now, Lorn is appearing at the Citizens’ in the starring role of Renton, the character played by Ewan McGregor in the 1996 movie.

“I can’t quite believe how lucky I am,” says the actor, his voice revealing his delight.

“And thanks to having the Choose Life poster on my bedroom wall I knew the speech off by heart before I even began rehearsals for this show.

“It’s a great piece of writing. (By Irvine Welsh). And in some ways, the speech makes Renton feel like the Scottish Hamlet. When he talks about hating the English it really hits home.”

Trainspotting, the story of group of friends and their journey to find some point to life via drugs, has been revived because of the success of the original play, which sold out the Citz in the early nineties.

And of course, the follow up movie has been filmed recently.

“This theatre play is faithful to the book, and also takes material from the original play,” says Lorn.

“But it has been also been restructured to incorporate elements of the film, which featured the same key moments, but in a different sequence.

Mark Renton is the cleverest of the bunch, in the midst of an existential crises when he turns from being happy-go-lucky into a drug dependent waster.

Lorn reckons the performance is made easier because he shares some of Renton’s thoughts.

“Yes, there are moments when Renton speaks when I think I’m not that far from agreeing with him. Now I get to go up there on stage and I’m so delighted to be spouting these words.”

He adds; “I can get on board with a lot of what he says, the fight that it’s in him and the angst. And I feel this is very far from a dated piece. In fact, it’s the most current theatre I’ve done in a long time.

The story is still set in the late eighties, but there are comparisons with politics today.

“This was a time of Thatcher coming to power, and there was a real sense of injustice in Scotland, and that feeling seems to apply today.

“Scotland didn’t vote for Thatcher and the country didn’t vote for Brexit, so there is a sense of being ignored.

“Feelings are more heightened than in the past fifteen years.”

The play is demanding however, his character goes on such an incredible journey.

“It’s a very strange and dark play and there’s so much going on with the character internally. Meanwhile, other characters are dying or destroying their lives.

“But at the same time Renton is clever; he’s thinking about the meaning of life while trying to factor in some of the political stuff that’s going on around him.”

Some of the speeches however are hard to get the mouth around. The drugs speech, for example; ‘We took morphine, diamorphine, cyclizine, codeine, temazepam, phenobarbitone . . ‘ and lists another 20-odd drugs.

“We get a version of this in the play,” says Lorn, smiling. “It’s a bit smaller and we focus on heroin, since it is the opposite of life.”

Lorn has seen the movie so many times he can’t remember.

“It’s always been one of my favourites. “When I go abroad and speak to strangers my Scottish reference point is; ‘Have you seen Trainspotting?’ And if they say no it means I get to steer them in that direction. It makes me so happy to be able to introduce it to them.

He adds, grinning; “Trainspotting is a heightened version of Scots life of course. But at the same time I think it’s a really good representation of a bunch of young Scots and how they feel.”

He adds; “But it’s also a very funny play.”

Lorn knows the Trainspotting world. He grew up in Edinburgh, just ten minutes from the film’s setting, in Leith.

He admits he was never going to be anything but an actor.

“I’m the younger of two brothers. My older brother is two years older and he is the intellectual. I’m the more creative, always hogging the attention and saying ‘Look at me, not at him.’

“I was always doing voices, pulling faces, looking for laughs, since I was five. Then when I realised there was a job called acting which paid you to show off, to be other people, to laugh and to cry, I knew where I was headed.”

Lorn adds, smiling; “I remember hearing David Tennant speak at the Conservatoire and he said ‘Only if you are not good at anything else should you do acting.’ And that was sort of how I felt.

Lorn began acting at the Lyceum Youth Theatre. His talent was such he was sent to meet a London agent. He went on to land a range of theatre work and at 18 was cast in movie Neverland, alongside Bob Hoskins and Keira Knightley.

“It was great experience, and so different from theatre.

He could have carried on acting. But he chose to study at the Conservatoire.

“By the time I went to drama school I actually had a few theatre credits. But I was focused on getting better at the craft. And at least I didn’t have to worry about getting an agent. I was already signed by the agent who has James McAvoy on her books.”

He adds, “I realise I’ve had such great opportunities. And my parents have been so encouraging, given this is such a ridiculous profession.”

Now that he’s starring in Trainspotting, Lorn’s brother has altered his impression of his younger sibling.

“I once did a BBC kids show for a year and I don’t think my brother watched it once. But then why would he?”

“But now he’s happy I’m appearing in Trainspotting because it’s so cool.”

• Trainspotting, the Citizens’ Theatre, September 14 – October 8.