Since then O'Carroll has portrayed Mrs Brown on radio, on stage and on television in the Bafta award-winning series Mrs Brown's Boys. But now things are set to get even more outrageous, with Mrs Brown's Boys D'Movie. It's the chance for Mrs Brown to tackle a crooked developer, the Government, the banks and the Russian Mafia when they collude to try and shut down her Moore St market stall.
"When you get to do a movie like this, there is a temptation to go a little mad and end up doing things that she might not normally do," suggests O'Carroll. "So, our first challenge was making sure we didn't go too overboard, like giving her superpowers, having her waterski, do magic tricks or think she's James Bond.
"I didn't want to betray her and I particularly didn't want to betray the audience," he adds, seriously. "I wanted the audience to go see this movie and feel like they're at a Mrs Brown movie, not just watching Mrs Brown in a movie -- if that makes sense.
"I certainly didn't want to do the cliched thing of taking her to Spain, Australia, America or Africa, which is usually what they do when a TV series becomes a movie, and see how she copes out of her familiar surroundings, in that Crocodile Dundee, fish-out-water type of way."
Consequently, Mrs Brown's Boys D'Movie is, as ever, set in Dublin, with her extended family helping their "ma" put the world's wrongs to right when she tackles inept, bureaucratic and corrupt authorities threatening to close her beloved Moore St market down.
"It's a love letter to Dublin, really, and the Irish tourism board should write Mrs Brown a cheque, because Dublin looks magnificent in it," he quips. "Seriously though, I just wanted to expand her world, tell one of the stories within that world and give the audience the chance to peek into the bits they know about, but don't usually see in the TV series, like her life at the market, selling fruit, and her interaction with authority.
"So, it's Mrs Brown at her challenging best, where she's challenging authority," O'Carroll continues. "That's why, for me, her best line in the move is when she says, 'They won't take me without a fight,' because you know they bleeding well won't take her without a fight -- and what a fight it'll be! Also, because it's Mrs Brown, you don't have to guess who's going to win."
For O'Carroll, playing Mrs Brown has made him a winner too, transforming him from an unknown pub-circuit comedian into a household name in Ireland and beyond. It's a success story he never imagined and one you'd never expect from his infectious, down-to-earth demeanour.
"I try not to think too much about my success or over-analyse things, but I'm definitely glad it came later in my career. If it hadn't -- if it had happened early -- I'd probably be a junkie by now," he suggests, shrugging his shoulders.
"My mam used to have a saying about success: 'You've got to treat it like disco music'. What she meant by that is don't think too much about it, just dance to it," he concludes.
"That's what I've been doing all this time, since that very first five minutes on the radio -- just dancing."
What: Mrs Brown's Boys D'Movie
When: Opens at cinemas July 24
Also: The live show Good Mourning Mrs Brown is coming to New Zealand in March 2016. Dates and venues to be announced next month.
- TimeOut