Nathan White has admitted he feared he would never realise his dream for Test match rugby during two injury-ridden spells.
Connacht's tighthead prop became Ireland's third oldest debutant of all time in Saturday's 28-22 victory over Scotland in Dublin, then conceded he fretted his Test chance had passed him by.
New Zealand-born White was all set for his Test debut in Ireland's autumn series in November, only to suffer an arm injury in training that then required surgery.
Head coach Joe Schmidt kept faith with the 33-year-old, however, and his impressive cameo off the bench on Saturday has boosted his chances of squeezing into Ireland's World Cup squad.
"When I injured my arm back in November that was very disappointing, but then to get fit and injure my back, there were definitely a few demons," said White.
"Connacht offered me a new contract though, so that really made me determined to get myself right and do right by them.
"And this opportunity came along, and that's just great.
"I don't know how many coaches would show the kind of faith that Joe has shown in me.
"He's backed me and given me a crack, and it's just fantastic to have had that chance.
"There were dark days in rehab but the carrot was always to be in the position to play in a game like this, so it's great to have done it."
Leinster stalwart Mike Ross remains the only player to feature in every Test in the Joe Schimdt era, and has the starting tighthead spot nailed down for next month's World Cup.
Marty Moore will provide the immediate back-up if he recovers from shoulder trouble in time as expected, leaving White battling it out with Michael Bent for the last prop berth in Ireland's 21-man World Cup line-up.
Bent's ability to prop on both sides of the scrum offers the kind of versatility Schmidt has already revealed he craves, but White's unfussy solidity may yet see him trump his main rival.
White himself was simply happy to have made his long-overdue Test debut, conceding he "felt like a kid again" on his international bow.
"Being involved in November and in the Six Nations in the camps, that definitely helped me in terms of knowing what was expected on the field," said White.
"I felt like a kid again myself, especially when you've got Paul O'Connell out there, a guy I've watched for a fair while.
"So I just really wanted to cherish the moment.
"If Joe's happy with what I've done on the field then hopefully I'll get the call to go back into camp on Sunday night.
"I'm just going week to week really at the moment, hopefully I can go back again.
"Marty Moore is coming back, and Michael Bent covered tighthead last week so there's plenty of options there."