There is the individual ambition and there is the team.
In rugby, often, the personal has to give way to the collective bargaining power in order to succeed.
This is what leads to regret for Jack Conan, even at the end of Leinster and Ireland's greatest ever year.
"At this stage last year, if you told me I'd go on and play six more times for Ireland, I probably would have bitten your hand off and said, 'that would be fantastic'.
"In saying that, I think it's just the nature of any athlete in any professional sport that it's never enough and when you get to any kind of level, you always want to push on."
It still sits uneasily with Conan that he wasn't on the starting line for a lot of the most memorable days.
"The big games I wanted to play in, to miss out on those big Tests against Argentina and the All Blacks at home, those are the days at the end of your career that you'll always remember. It's tough looking back and not having been selected for those," he stated.
"Hopefully, I'll push on and get more opportunities in those really high-intensity, high-pressure moments because that's why we do it.
"I don't think I'd ever look back and say I was happy with that."
The unsatisfactory moments were not all reserved for the green shirt.
"I experienced so much and achieved a lot of success, especially here at Leinster," he added.
"But, I look back at not starting that (Champions Cup) final over in Bilbao, only playing the two games in the Six Nations.
"You're always going to be hungrier and never settling and wanting more for yourself.
"Hopefully, in 2019, I can push on and, obviously, it's a massive year for Irish rugby and, please God, things go well and I'll be on the plane over to Japan.
"But, there is a lot of rugby to be played between now and then, especially here in Leinster where we're looking to go back-to-back champions in Europe."
Taking a peek around the corner, England will come to Dublin in the Six Nations opener on February 2.
The amateur-era Irish trial of 'the probables' versus 'the possibles' is just a distant memory these days.
However, the possible Conan will have to out-perform the probable CJ Stander Thomond Park tomorrow to have any chance of ripping away Ireland's No.8 shirt.
"Any time you're going up against one of the other provinces it's a good opportunity to put your hand up against someone who could potentially be ahead of you or getting the nod to be starting ahead of you.
"It's going to be massive for me and I quite enjoy those opportunities when I get to play against any of the other internationals," said Conan.
"I look forward to going head-to-head with him."
The temptation to have one eye on Stander has never been there for the 26-year-old Conan.
"I wouldn't watch too much rugby in my spare time," he admitted.
"What he does and the way he plays is nothing to do with me. It has no impact on how I play or what I do, so I don't worry about it.
"If he's going well, that's great. It just adds to the competition in Ireland camp.
"It's not something I think about much."
That will change for this week, at least.