There have been moments this season when it is worth reminding yourself that Owen Farrell is 22. Off the pitch, sitting fresh-faced on a sofa in a TV green room, he looks his age. On it he looks anything but. This season he has played like a cold-blooded, narrow-eyed veteran, an old pro who has seen it, done it and long since crumpled up the T-shirt in the bottom drawer.
Farrell has become a dominant No 10, a suitably granite presence at the heart of a Saracens side threatening to triumph domestically and conquer Europe too. Beginning tomorrow, the next three Saturdays will define Saracens' season, a brutally demanding finale to a campaign that promises so much but will mean painfully little without the end result. First it is Harlequins, a contest they start as strong favourites, next it is Toulon in the Heineken Cup final at the Millennium Stadium and finally, should tomorrow go well, comes the Premiership final at Twickenham.
It won't end there for Farrell, nor for the man sitting at the other end of the sofa ahead of their appearance together on BT Sport's Rugby Tonight, Chris Robshaw, his England captain and his opponent this afternoon. The demands of a northern hemisphere season will be replaced by the unique challenges of touring New Zealand. It is a run of rugby – including a Lions tour for Farrell – on which the sun will not set. There are those who rightly fear the demands that are placed on the best players, but when you are up to your neck in it and – and this is the key ingredient – winning, you never want it to end.
"Yeah, love it," says Farrell. "It's brilliant. The exciting thing with everything I'm involved in – and I'm sure Chris will feel the same – is it's growing and growing and growing and we're on the right path and getting better and, hopefully, that never stops.
"Some of the rugby we have been involved in this year I would not want it any other way. I have not looked back on it too much but it has been a brilliant year to be involved in and exciting, and one that I think I have learnt a lot from.
"You feel drained after it has all finished," he adds, "but once you are in it, especially in games like we are at the minute, it is not hard to come to training in the morning and feel good because these are the games you have worked all year to play in."
This afternoon's fixture at Allianz Park is billed as north London's roundheads against the cavaliers from the capital's south-west. Except Saracens scored 25 more tries over the season's 22 Premiership games, and ran in six tries in that Heineken Cup semi-final against Clermont, a result and performance unmatched by an English club in Europe.
"It was a different class, wasn't it?" says Robshaw. "We played Clermont twice in our pool in the Heineken, and we came close once but we didn't do what these guys did and manage to shut down Clermont completely. We went over to their place and were chasing shadows a bit so for them to put 40-plus points on them was an incredible performance."
Farrell was at the heart of it, scoring one of the tries. "I thought we were very good," he says. "It's the most joined-up performance I can remember in a Saracens shirt. It wasn't just one area of our game where we looked good; it was a collective effort from us all. But you don't want to be too over the moon. It was a semi-final, and you want to come off saying that having won the final."
Farrell has played in 12 Premiership games this season and they have won them all. Ian McGeechan identified him as the "principal reason" for Saracens being where they are, nine points ahead of the rest in the Premiership and in the Heineken Cup final. This is his third season in the Premiership and his game is becoming ever more rounded, a No 10 who can manage a match. This week Danny Care, his England half-back partner and another opponent tomorrow, praised his dominance – and bossiness.
"You're always looking for ways to get better," says Farrell. "Not just the attacking side of my game, but everything. We have evolved the attacking side of our game at Saracens, scored more tries and made more breaks, and that has definitely helped me to become a better attacking player as well.
"Rugby is about playing where the space is – if there's 14 men in a defensive line and one guy covering the backfield, that's where the space is; if there's three dropped back, it means there's space out wide and it's on to play. It's all about making good decisions."
Saracens surprised many, Robshaw included, with the level of their performance against Clermont. It is a height they will do well to reach again but, given their and Farrell's season, and the mood around the club, there is reason for them to believe in a repeat.
"Why not? We've set a standard for ourselves now," he says. "That's the key for us, we want to make sure we get better and better and don't just rest on one good performance. Although we've been pretty consistent all year, we probably took it to a different level that day. That's what you strive to do again, take it to a different level."
The Aviva Premiership semi-final between Harlequins and Saracens kicks off at 2pm Saturday, exclusively live on BT Sport