"I lost friends when I moved from Glentoran to Linfield, but I don't regret it," reflects Justin McBride on his cross-city switch back in July 2001.
At the time, the move caused shockwaves, particularly as McBride was a fans' favourite and a lifelong Glenman born and bred in east Belfast.
These days, such moves are much more common, as evidenced by Linfield's double swoop for Conor Pepper and Navid Nasseri yesterday.
Jamie Mulgrew, Andy Waterworth, Jimmy Callacher and Jordan Stewart all had spells in the east before moving to Windsor, while Marcus Kane, Joe Crowe and Cameron Stewart are all former Linfield players.
Going further back, Sammy Pavis, Warren Feeney Snr, Johnny Jameson and Raymond Campbell also dared swap tribes and McBride reveals he spoke to Pavis about his own move.
"I met Sammy on the Belmont Road," says McBride, who won two titles and two Irish Cups with Glentoran. "And I asked him about his move.
"He said, 'I still get called Judas 40 years later!', and I get that. I know the hurt it can cause some people, but I stick by my decision - even though it wasn't my decision to leave the Glens.
"I grew up on the Newtownards Road, I was always a Glenman and I used to watch the games - including getting a police escort to and from Windsor.
"All my friends were Glenmen, I mean my whole social circle, and I spent 11 happy years at the club, but my move wasn't black and white. I didn't jump ship to the Blues.
"I was put on the transfer list by Roy Coyle, who had signed Darren Fitzgerald and wanted a change, so it was clear I was not going to be in his plans.
"I don't think that Glentoran fans recognised that, but David Jeffrey did.
"He had seen the writing on the wall and knew I would be leaving Glentoran.
"Coleraine came in for me as well - and offered lots more money - but my decision was not based on money matters.
"I had just had a new baby and the travel was also a factor.
"It was a bit scary having interest from Linfield, bearing in mind where I lived and the fact that all my friends were Glenmen.
"I lost quite a number of friends. Well, not friends, I would call them supporters.
"I knew what it meant, but I wanted to prove Roy Coyle wrong and other clubs didn't matter at the time, bar Linfield and Glentoran.
"I got a couple of threatening letters, nothing as bad as Johnny Jameson who I think got paint thrown at his house, but I didn't like going back to The Oval.
"You could see the veins standing out on people's faces on the terraces.
"I still don't go now. I have a 250 appearance card that gets me in any time I want, but I don't use it. When I did go back, I felt uncomfortable. I maybe don't get the credit for what we achieved at Glentoran.
"I don't think I really performed for Linfield so I was never accepted by either club in the end. I was stuck in the middle but I did try my best for David Jeffrey.
"A week after I signed for Linfield, I was involved in a car crash - people used to joke that it was Coyler - and that exacerbated back problems I had at Glentoran, two prolapsed discs in my back.
"I didn't do as well as I thought I might have at Windsor but I'm not going to say I regret the move. I stick by it."
Three years later, Chris Morgan left Windsor for The Oval and in his first season scored a late winner against the Blues to effectively hand control of the title over in what was soon dubbed 'Morgan Day'.
The Saintfield man was also targeted by boo boys but insists any regrets he might have are more to do with unfulfilled promise.
"I was cast as the villain of the piece but the truth is I wasn't offered a new contract at Windsor Park and I knew it was coming," he explains.
"I thought I was going to sign for Ballymena, that was in my mind, but then the Glens came in and Roy Coyle helped me make my decision.
"He had played for Glentoran and Linfield and managed both teams, he was aware of the impact as he had been there and done it himself.
"I was apprehensive but he told me if I played well, I would win the fans over. I had seen what Justy went through, although me leaving the Blues wasn't the same.
"My dad was a Glenman and took me to games as a kid but it took a while for Glenmen to take to me. I scored the winner against the Blues in the League Cup Final and people still talk about Morgan Day so that helped.
"I don't regret the move, I have more regret at how things worked out at The Oval. Things started to go downhill after we won the League in 2005 and that was a missed opportunity in my opinion.
"But I won medals there that I wouldn't have won anywhere else and as a footballer that's what you want from your career."