'An ex girlfriend once told me I had evil eyebrows, not eyes , eyebrows, so maybe I slipped into character easily!’
For the actor, from Slane, in County Meath, is a massive Star Wars fan, who has a colossal collection of over 50,000 individual Star Wars items clogging up a room in his home.
He told the Sunday World: “My cousin Patrick O'Reilly started me off by sending me stuff when I was a kid and it literally grew from there.
“Probably the three most treasured items I have are autographs from three of the original cast who are now dead, Kenny Baker who played R2/D2 Jeremy Bulloch who was Boba Fett and David Prowse who played the original Darth Vader.
“I haven't done the Skelligs trip because to be honest I think the recent movies go against the iconic and sacred story.
“That said if they rang and asked me to be in the next instalment I wouldn't say no.”
“No” is a word O' Brien got used to hearing as a jobbing actor or as he puts it, 'It's taken me twenty years to catch a good break, acting is 99% rejection letters so you have to make the most of the chance when it comes.
“I have been an actor since I was 17 and played everything from Shakespeare to the lead role as a dog in a play in Cork so I have played both lead roles and roles on a lead!
“The Fair City gig came about through the usual route my agent got me the audition, these days it is not a case of going into a room and doing a reading you record yourself reading the part send in the tape and sit back and wait.
“Apart from the quality of everyone involved there is a real sense of soap opera history about the place, Liam Kearney who plays my dad, Con, was in Glenroe, Aisling O'Neill's dad was in The Riordans, and Jim Bartley who is Bela goes back to RTE's first soap opera Tolka Row so there is a real sense that we are carrying on a long standing tradition.
“I like James as a person, put it this way I'd go for a pint with him, he has his evil side, but we all have that but like the rest of us the key to redemption is within him, he's not all bad.
“An ex girlfriend once told me I had evil eyebrows, not eyes, eyebrows, so maybe I slipped into character easily!
“It's a bit different here than if you were starring in the UK soaps, here if someone recognises you it's like, 'Oh that's your man from Fair City' and everyone moves on. although I had one surreal experience.
“I was showering after a workout in the gym and a guy using the shower next to me copped who I was and started chatting away about the plot lines, that was a bit unusual to say the least, certainly it was hard to carry on a conversation,
“The brilliant thing about playing James Rafferty is that every time I pick up a new script I have literally no idea what it will contain he could be getting up to anything, I'm grateful to have the role and I am living for the moment.
“If I ever lose the run of myself I remember the Hans Solo quote, from Star Wars, 'Great kid, don't get cocky' and that keeps my feet on the floor.”