If England's performance at the Stade de France on Saturday told us anything about international rugby, it is that there is absolutely no hiding place for rookies in these contests.
The likes of Jack Nowell and Jonny May received no chance to adapt to the rigours of tackling France before they were either perpetrating errors or suffering a black eye and broken nose, as happened to May. It was a bruising, brutal induction to the RBS 6 Nations and one which demonstrated how the physicality of the sport has advanced to the stage where going into every challenge is an exercise in self-sacrifice of the body.
With hindsight, the English were badly exposed in the first quarter, and it spoke volumes for their tenacity in the subsequent hour that they came so close to engineering an enthralling victory, despite trailing 16-3 in as many minutes in Paris. To some extent, they were the architects of their own downfall; this was a match where too many of their ensemble committed mistakes at crucial moments. And yet, despite these errors, and oblivious to the whirlwind which engulfed them throughout the opening quarter, the visitors were still only denied by the late brilliance of teenager Gael Fickou.
That climax must have been a kick in the stomach for the players and their coach, Stuart Lancaster, and it was to their credit that there was no clutching at straws in the aftermath. The question now is whether they can rebound from the defeat - as Wales did last season - and use the memory of their last-gasp loss to galvanise themselves in the rest of the campaign. If they can, then Scotland had better beware at Murrayfield, because we witnessed sufficient pyrotechnics from several of their precocious talents to be aware that if England are not yet a great side, they are close to being a very good one. But if they cannot, then there will surely be few better chances for Scott Johnson's personnel to regain the Calcutta Cup when these combatants square up on Saturday.
It will be interesting to see whether Lancaster continues to put his trust in so many youngsters or recalls a few of his more experienced stalwarts. He knows that there will be no possibility of championship success or Triple Crowns if his team does not claim victory in Edinburgh but, equally, most of his charges performed well at the weekend and, but for a few unkind bounces of the ball and some uncharacteristically sloppy kicking from Owen Farrell, they could have completed their greatest-ever fightback in the championship.
So too, the English have unearthed at least half a dozen players with the quality to unsettle and dismantle opponents on their own. Their locks, Courtney Lawes and Joe Launchbury, were both outstanding while flinging themselves into the fray; Billy Vunipola, who seemed capable of moving forward, Lomu-style, despite having two or three tacklers clinging to his legs, offered the sort of display which proves how difficult he will be to stop if he gains any decent possession at Murrayfield; and Mike Brown and Danny Care both served up lung-bursting performances and were instrumental figures in their side's recovery. As for Farrell, the danger for the Scots is that he responds to his lapses with an afternoon where everything he kicks goes sailing between the posts.
In short, these are not the kind of adversaries who will be indulging in self-pity this week.
None the less, the Scots have to heed the lessons from Paris, which means they should surge out of the blocks and really strive to unsettle their rivals straight from the kick-off. There were enough little gaffes and signs of weakness from England in their defensive duties to suggest that the majority of their new recruits prefer an attacking strategy to playing the percentages. In recent years, these matches have tended to be tedious wars of attrition, resolved by the boot, but one suspects that penalties alone will not guarantee success in this instance. Scotland need to be bold, adventurous, and trust their instincts; they should grant such influential figures as Stuart Hogg, Sean Maitland and Richie Gray a licence to thrill by rampaging into England and testing their mettle.
If they do so, and can manage to put early points on the board, it could be much harder for England to recover than it was against the French, for one important reason, namely the crowd. Once again, the audience at the Stade de France subsided into silence for much of the second half while England inexorably clawed back the deficit and it was impossible to believe there were 80,000 spectators in the ground. That is one of the problems with that particular arena, but it will not enter the equation at Murrayfield- not if the hosts provide anything for the fans to get excited about.
It should be another cracking contest, one where Scotland have to keep remembering their foes are acquiring the unwanted habit of going down in tight games. But they must also expect a backlash from the English, so it will be no place for the faint-hearted.