Like a couple who have just moved in together, Jofra Archer and the England team are still coming to terms with each other's little ways.
Both know this is a special relationship. And both know it's made to last. But, as they settle down together, they are still marvelling at their new partner's qualities, working out what makes them tick and wondering why on earth they keep leaving the top off the toothpaste.
Take Archer in this match. In the first innings, with his team still riding the crest of the drama of Leeds and the game to be defined, he went missing a bit. It wasn't just that his speed was down a little - his average first innings speed was still a respectable 85 mph; his highest was a more than respectable 91 - but that he was unable to replicate the probing lines and lengths he had managed at Headingley. He finished with 0-97 from 27 overs and Australia built a match-defining position.
In the second innings he suddenly went up a gear. His top pace was 93 mph and his average was 88. He was, once again, the high-class fast bowler England have needed for so long. He produced an invigorating spell of fast bowling that, for a moment, threatened to drag England back into the match. But Archer and the equally admirable Stuart Broad had to be rested and, honest though the rest of the attack is, they lack the bite of the opening pair.
Also read: Bayliss holding out for a hero
The catalyst for the spell seemed to be some sledging from a couple of Australian players when Archer batted. Matthew Wade and Travis Head had been particularly vocal, appearing to question Archer's commitment to Hobart Hurricanes in the Big Bash. It didn't seem especially serious stuff - certainly there was nothing inappropriate, though Adelaide Strikers' supporters may have been encouraged by it - but it did seem to irritate Archer. When Head came in to bat he was waiting.
Immediately, Archer's pace went up to 90 mph. His first delivery beat an airy push, his second was dug out and his third, a bouncer, saw Head jerk out of the way. Shortly afterwards, the batsman was struck on the arm by another short one and the pair exchanged words. The next ball, again well over 90 mph, was driven for four but the one after that, a searing inswinger to the left-hander, knocked out his middle stump. The spell to Wade was not quite as dramatic but again, Archer got his man.
What can we conclude from all this? Well, firstly, that it probably isn't too clever to rile Archer. Just as Dean Jones found when he complained about Curtly Ambrose's wristbands or South Africa found when they bounced Devon Malcolm, it's sometimes best not to provide any extra motivation for fast bowlers. Archer, under that calm demeanour, is a fierce competitor and thrives in the heat of the battle. Maybe the England management, and Archer himself, need to find a way to unlock that aggression on demand. You would think it may be a task for the team psychologist.
But, from an England perspective, there may also have to be some tempering of expectations. Yes, Archer can bowl fast. But it is hard and it requires many factors to fall together if it is to happen. So in Leeds, for example, Archer did not feel it was necessary and concentrated on control and movement. And on the first day here, with a fierce wind and a wet outfield, he was simply unable to replicate the same rhythm. Trevor Bayliss rated the conditions "the toughest I've ever seen cricket played in." He's not a man prone to hyperbole.
Broad seemed to concur. "The outfield was very wet," he said. "It's cut very short, so it churns up a bit and it's hard to get grip when running in. You can't charge in. Your feet were almost sinking behind you." Put simply, Wednesday's conditions would have troubled any seamer. For a young man brought up in Barbados and playing only his 31st first-class game they were hugely testing.
It's important to remind ourselves about that inexperience. That number of first-class games is almost a third of the number played by Craig Overton, who is less than a year older. Archer is learning his trade. There are bound to be days when it shows.
Unlike just about everyone else who has played for England in recent years, Archer hasn't come through the ECB's pathways. As a result, there is little knowledge for the England management to draw upon: few captain or coach reports; no assessments from Loughborough; no feedback from Lions tours. England know they have something special here, but they don't know many of the details of how Archer works or how he can best be utilised. There will be days when that shows, too.
There are some potential areas of improvement, though. Archer would appear not to be the most enthusiastic embracer of warm-ups - he often bowls spin on the morning of games and sometimes on the day before the match - and instead seems to prefer to ease his way into games through bowling. That's understandable. If he is required to bowl in match situations as often as England seem to demand, he doesn't want to waste any deliveries in training.
But, given the importance of utilising the new ball in Test cricket, that is a habit that may need to change. He needs to hit the ground running. He needs to adapt and learn. The England management, whoever that is in a few weeks, need to help him come to terms with that.
Equally, though, they have to understand that he cannot be a strike and stock bowler. Mitchell Johnson, for example, bowled only three or four-overs spells during that peak period he enjoyed in 2013 to 2015. Archer's first spell on Saturday was nine overs and, 16 overs later, he was recalled for a second spell. That workload may be sustainable for a classic English seamer - the likes of Overton - but Archer's ceiling is higher than that. He has to be looked after a bit more. Weariness - both mental and physical - may well have played a role in his declining pace since his Test debut at Lord's.
Maybe we should be aware of some alarm bells here. We now know that Archer had a pain-killing injection in his side at the end of normal play in the World Cup final and ahead of the super-over. We know, too, that he had undergone injections ahead of several other games. Is it right that four-months into his England career, he is already requiring such treatment? He has a precious talent; he needs resting and nurturing and protecting as much as he needs medical help to continue playing.
Most of all, we have to be realistic. That's the management, the media and the supporters. Even the very best in the business of fast bowling - the likes of Malcolm Marshall and Richard Hadlee - did not bowl flat out every day. Archer showed at Leeds that he could be successful by cutting his pace and concentrating on control and movement. We shouldn't just judge him by the speed gun. He's better than that.
At Sussex, they believe he is at his best pitching a full length that would hit a couple of inches below bail height on off stump. With his delivery point so close to the stumps and his ability to move the ball both ways, such a length invites the drives but offers the promise of several modes of dismissal. The bouncer is there only to ensure the batsman isn't too quick to come forward and as a shock. It shouldn't be his stock ball.
Archer has already helped England to that elusive World Cup title. He's already achieved the highest pace recorded by an England seamer. Bowlers like this come along, in England at least, very rarely. But there are going to be a few poor days on the journey and, if he's to fulfil his obvious potential, there has be deeper understanding of what is reasonable to expect and demand from him.