When Brian O'Driscoll joins the ranks of rugby's Test centurions on Sunday he will be afflicted by the same nerves that marked his debut.
Ireland's opening autumn international against Australia at Croke Park heralds the arrival of another special milestone for their enduringly brilliant captain.
With 93 Ireland caps and six Test appearances for the Lions in the bank, O'Driscoll will become the 11th player to achieve the century when he faces the Wallabies.
Only Australia openside George Smith, named on the bench for Sunday, has reached the mark faster.
In a neat piece of symmetry, O'Driscoll made his debut as a 20-year-old replacement against the same opposition in 1999 — and the similarities between occasions will not end there.
“I was really looking forward to my first cap and didn't start feeling nervous until the fireworks went off when Australia came onto the pitch,” said O'Driscoll.
“I wasn't expecting that. Once the whistle went for the start of the game all those nerves evaporated.
“I still have those nerves — if you don't the mind isn't sharp.
“You have to be on the ball against Australia so if you're eating your pre-match meal without any problem then there's an issue there.
“You need to be forcing your food down. The butterflies focus the mind and get you ready for combat.”
Lions years have a habit of reinvigorating great players and so it proved with O'Driscoll, who put several indifferent seasons underlined by niggling injuries behind him to take the RBS 6 Nations by storm.
The 30-year-old became only Ireland's second Grand Slam-winning captain, producing two man-of-the-match performances and finishing as player of the tournament in the process.
Further heroics followed on the Lions tour to South Africa, where he was outstanding before being forced home after the second Test because of concussion.
The searing acceleration that marked his earlier years may have been eroded by injury and time but, older and wiser, the Leinster centre is as creative as ever and remains utterly fearless.
His captaincy record with Ireland reads 39 victories in 56 matches dating back to 2002 yet, despite his long service, he appreciates the job as much as ever.
“We're in the fortunate position of having a lot of great leaders around so the workload is shared,” he said.
“But it would be strange to be playing in an Ireland international and not be captain.
“Keith Wood was the last Irish captain I played under and that feels like an eternity ago.
“I enjoy it as much now as I did in the early days, though it probably comes more naturally to me now.
“You always look forward to coming back into the Irish squad. It's the pinnacle of everyone's career.
“I have great hunger for the game at the moment and hopefully we'll pick up where we left off in March.”