Over the years I've seen good teams win games because of hard work and preparation - and great teams win games for the same reasons but also when they shouldn't.
Last Friday night had all the hallmarks of an unwanted fixture from a Leinster players' point of view. Wales away on a cold winter's night during the Six Nations period is hard to digest and even harder to perform in.
It's even worse when at half-time you're down against a side that you would be expected to beat in the normal day-to-day business of the PRO14. But this is where professionalism kicks in.
After the slug-fest in the RDS the previous week, this trip was a reprieve against an Ospreys side that were on the rebound following a torrid six months.
Containing them was a priority and winning was a bonus because they were up for it as Leinster were the team to beat, being at the top of the conference.
The younger members of the team dragged the more experienced players through the game and back to winning ways.
Once again, the Leinster young guns performed, guided by the foundation play of Rhys Ruddock, Michael Bent and Jamison Gibson Park.
It made little difference to these youngsters where the venue was or who the opponents were.
Tommy O'Brien's try was scored with the confidence of a player playing in the RDS in springtime.
In fact, the skill level of these Leinster players in, once again, testing conditions was quite impressive.
However, this game was not won by skill; it was won because of belief.
The Ospreys showed a lot more structure than they have in previous months and took their opportunities well, but Leinster have resilience and confidence.
This gives them the mental and physical ability to strike when the opportunity occurs.
Once again, the competition for places within the club means that the team's performance levels rarely drop below the high standard they have had all season.
It will take a club with the same depth in talent to match them and this weekend's game against Glasgow will bring Leinster in that direction. Glasgow Warriors will be more formidable opposition, and being home game it's a must-win.
Glasgow are not the force they once were but the quality is still there and at this stage of the season Leinster need more testing.
After this game the Blues head to South Africa for what will effectively be warm-up games for the European Champions Cup quarter-final against Saracens.
It would normally be ideal for Leinster to go to South Africa post-Six Nations with a full squad and play and train with what's left of the summer sun at their backs.
The international players could rehab after a tough Six Nations and gently be reinstated to their club 23 but once again this season is different.
Leinster will need to bring a large squad to South Africa - larger than would be normally needed for two games, a squad of players that would replicate the standard training ground intensity at headquarters.
In some ways the two games down there will be immaterial because the province are going to have to once again increase the intensity in their training to match European standard.
If they get this from the Southern Kings or Cheetahs, even better, but a mix of rehabilitation and European re-focus is what is required on this trip.
With the cancellation of the Ireland v Italy clash, pressure might come on Leinster management from a selection point of view.
Irish players are going to need game-time and Irish borderline players will need an opportunity to be reviewed by the Irish management.
From Ireland's point of view, both that of the players and management, they will be frustrated they will not get a chance to put in a performance against Italy that both badly need to banish the 80 minutes at Twickenham.
They also need game-time to look at selection changes for the French game. Both of these issues will land at Leo Cullen's door and, once again, Irish players playing in a Leinster shirt are more likely to perform better than in an Irish one.
The loss in Twickenham was like no other loss - this Irish team is a team playing with no structure, composure or direction.
We pretty much have a bunch of talented individuals executing structures from previous regimes and current clubs.
This isn't all Andy Farrell's fault as the blame can be spread across his coaching staff, if not fully on them, but it doesn't help Leinster's cause.
While Leinster provide the lion's share of players to the international set-up, they need to also keep a distance from the negativity and self-doubt of the Irish camp.
What will transpire is that Leinster players will relish being back in the blue jersey; it will be exactly like their refreshing return to the province after the World Cup.
The only difference is they will not have the same lead-in time to hit peak performance but will have a set-up that gives them the platform to compete against the best in Europe once again.