As a kid, he played soccer and Gaelic football, which was his passion. His boyhood dream was to play for Kildare at Croke Park.
But having taken up rugby at 15, his talent blossomed through the Naas/Leinster Youths set-up and into the province’s sub-academy after leaving school. Then one day he had his eyes opened.
He had thought of maybe, one day, paying for Leinster, but admits, then 18, he had never really backed himself to do so, until he was called into a meeting by the then Leinster Academy director Colin McEntee toward the end of the 2011-12 season. Wayne Mitchell and Girvan Dempsey, two hugely influential elite player development officers who have impacted Byrne's career, and the province's fitness director Dave Fagan, were also there.
They asked him where he saw himself playing the following season.
He said he’d love to make the Irish Under-20s and the UCD firsts.
They told him he needed to start believing he could make the Leinster first team.
“I would have laughed that idea off until that meeting. After that, I decided I wanted to play for Leinster. I wanted to wear that blue jersey. I don’t think it was too long after that before I made my debut for Leinster.”
Joe Schmidt made him Leinster's youngest ever debutant against Connacht at the RDS in December 2012, even though, remarkably, he'd only played his first game for Naas CBS about four years previously. An horrendous run of injuries led to a three-year hiatus before he would play his second game for Leinster. At this point a year ago, Byrne had only played four games for the province, before a breakthrough campaign featured 20 games and ten tries.
Today is Byrne’s third game at the Aviva but first against Munster.
“Every since I started watching rugby, even before I began playing, you always watched the Leinster-Munster games. Underage playing Munster was always a step up as well. There was always added bite. It was the one game as a young fella I always wanted to play in. From the start of the week you can feel that extra intensity and feeling in the air in everything; in the team meetings, in the gym, on the pitch, and I can’t wait to experience it.”
He remembers sitting in the stand two seasons ago and hearing that roar. He loves the roar.
“When I was younger, I often wondered why there was an away goal advantage in European two-legged games in football. I didn’t understand it. It was the same goals, the same players, but it’s only when you experience what a noisy home crowd can do for you. It does give you that extra lift.”
“As a player you’re just playing on pure adrenalin. You feel like you can run for days. It’s unreal. Hopefully we can give the crowd a good performance and bring them to the RDS for the Montpellier game, and every game from them on.”
Even before Gaelic football took hold, he and his brother Sam, an Republic of Ireland Under-21 international now with Everton after coming through the Manchester United academy, were “big soccer heads”.
Born in Dublin, the brothers played football with St Francis before his family relocated to Kill when he was nine, and they joined Naas AFC.
“I kinda realised I didn’t have the finesse for soccer, so I took up Gaelic football. That was my number one passion. All I wanted to do was wear the Lillywhites jersey and play for Kildare in Croke Park,” he admits in the Union Café in Mount Merrion on Thursday, not far from where he shares a house with five mates, including Leinster team-mates.
Ironically, he begged his mum not to send him to Newbridge, because he would have to play rugby there, and after a year at St Patrician’s, swapped there for Naas CBS.
With Patricians, he was part of an All-Ireland Gaelic football U-14 winning team. He liked playing through the middle, be it midfield, centre-back or centre-forward; catching and running with the ball.
“But I wasn’t the best at shooting. I could balloon a few wide. I’ll admit to that,” he says with a laugh.
His age-group at Kill GAA were also above the norm, and Byrne made the Kildare U-16s and U-17s, but by the time the Kildare minors were on his radar, he was also part of the Leinster Youths rugby squad.
Towards the end of his first year at Naas CBS, at the age of 15, someone suggested he might be good at rugby. It took him a while to understand the game, but he liked the physicality, and the way the game was refereed. The following season Byrne broke into the Naas CBS senior cup team, and his natural talent saw him fast-tracked into the North Midlands and Leinster Youths set-up.
Eventually, something had to give, and it was Gaelic football.
“Sometimes I literally could barely move between training for one team or the other. I sat down with my parents. I had to make a choice. I guess I wanted to see how far I could go in rugby. The fact that it was professional and worldwide gave it that extra bit over the Gaelic, but it was a very tough choice at the time.”
For Sam, who is only 18 months younger, it was always going to be football, which meant the younger brother joined St Joseph’s Boys. This in turn meant plenty of driving for their dad, Keith, who runs his own courier business, and their mum Gillian, who teaches beauty therapy in Blackrock. They ferried the boys everywhere.
“I owe my parents a lot. I know it’s clichéd, but without them it wouldn’t have been possible.”
In due course Sam’s football abilities led to a move to Manchester five years ago. Byrne admits it’s only since his brother moved that he realised how much they did everything together – Gaelic, football, play stations – and bounced off each other. Whereas Byrne has his mates, his college life in UCD, Leinster and the family 30 minutes away, he admits his brother took on a more daunting challenge.
“I admire him big time. He had just turned 16 when he left home. He had to grow up quickly.”
Sam also suffered a freakish double leg break, akin to Séamus Coleman, in a training accident last season.
“But talking to him lately, he says he’s training really well, his mindset is good and hopefully he’ll be back to where he was.”
Byrne went over to see Sam play for the Manchester United Under-18s, and has visited him at Everton the summer before last with Peter Dooley and Peader Timmons.
“I never used to understand how parents would get so wound up watching games, but that’s how I felt watching him. I felt more nervous watching him play than when I play.”
Christmas get-togethers can be male dominated, although their 16-year-old sister Abbie could hardly be in a better locale than Kill for her love of horses. “She’s the brains, and she loves animals, and big into horse-riding. She spends every bit of her free time at the big equestrian centre in Kill.”
Looking back, Byrne reckons he was blessed to come through Naas and the Leinster Youths’ system. He was taught good habits quickly, and it also led to two years in the Leinster sub-academy and then the full academy for three years, along with a scholarship in engineering at UCD, where he’s now doing his Masters.
“I owe UCD a lot as well. I tried to commute in my first year. I’d be doing gym at 7am, then going to lectures, training with UCD at night, and Leinster skills’ session thrown in, so I had to move up to Dublin, and without the Ad Astra I don’t think I would have been able to.”
There were some tough times though. Shortly after that Leinster debut, playing for UCD against Lansdowne on the latter’s 4G pitch, his foot was trapped in a tackle, and he suffered a fracture in his ankle. The offending piece of bone couldn’t be removed, and he was told that if it didn’t rejoin, he might not be able to walk properly again.
“I was actually quite worried that my career might be over. I actually used the match fee from my debut to go to an hyperbaric oxygen chamber. I spoke with Gordon D’Arcy at the time, who was extremely helpful. He’d been there after breaking his arm quite badly. I spent that money on ten sessions in the chamber just off Jervis Street. Thankfully, the bone joined back and that ankle, touch wood, hasn’t given me too much trouble since.”
Having missed the Six Nations Under-20s, he targeted the U-20 World Cup only to tear his quadriceps badly in training. He returned for the 2013-14 U-20 Interpros against Connacht, playing in midfield alongside Garry Ringrose, before suffering syndesmosis, a high ankle strain, against Munster which again required surgery.
“It’s actually quite common,” he says, pointing to a protruding thin straight strip from his lower ankle.
He returned for the 2014 U-20 Six Nations, but in his last game for UCD, this time at home to Lansdowne, before the Under-20 World Cup in New Zealand, he sustained a broken fibula in his right leg. This time he points to the scar and plate above the aforementioned wire, which also had to be reset.
Though fit again for the 2014-15 season, his second in the Academy, with Matt O’Connor he felt he was well down the pecking order. Playing for the Irish Sevens revitalised his career. He loved the space to run with the ball, and the higher workload and involved.
He vowed to give it his best shot in his final year at the Academy, 2015-16, whether for UCD, where the debt to John McLean and Bobby Byrne is also immense, or the Leinster As.
During the Six Nations window, he bridged the three-year gap after his Leinster debut in horrid weather away to the Dragons, before scoring both at home and away to Zebre.
“That home game was special. I was extremely nervous. I remember Josh [van der Flier] my housemate, threw me the last pass when I scored, and he was the first one there to congratulate me. There’s a very nice picture that we have in our house. That was a very special moment. Once I got the taste of that, I knew that’s definitely what I wanted.”
A one-year senior development contract, and last season’s Pro12 meeting with Connacht at the RDS at the end of October was one of the biggest landmarks in his career.
“They’d beaten us quite convincingly in the Pro12 final the season before so it was a massive game for the team and for me. I loved every minute of it, and the roar of the RDS. It was probably one of the easiest tries I’ll ever score but it meant a lot to me.”
A hat-trick followed in his next game away to Zebre and another in Leinster’s next outing at home to the Scarlets. His form earned him a European Champions Cup debut away to Northampton, and another start a week later, when scoring twice in Leinster’s romp at the Aviva, and he also played in the quarter-final win over Wasps.
Now, after last season’s breakthrough campaign, he needs to back it up.
“Last year felt like my first proper season as a pro. I loved every minute of it. But still every game you feel you could have done better. It’s the same this season. First of all I just want to play every minute I can play, and I want to play well, and I want to be the first-choice winger for Leinster. That’s my goal but I’m sure it’s other lads’ goal as well, and that competitiveness is driving us all.”
To get there, he knows that he has to be solid and dependable.
“Then for me, as well, I want to have that X factor. I want to score tries and I want to set up tries, and bring something extra to the backline.”
He’ll be nervous today. But that’s good.
“I like the nerves. If I wasn’t nervous, I’d be worried. I used to let the nerves control me, but I’ve learned to use them to my advantage, to have that feeling of being light on your feet and you can feel the atmosphere.”
And feed off it.