Life is difficult when you're 38 and making your living as a fast bowler.
It's not just that you ache where you used to play that's the problem. It's that bad days are no longer classified as bad days; they're classified as a sign that you're finished. Washed up. Broken. Ready for retirement.
James Anderson certainly didn't enjoy his happiest day in cricket on the first day at Emirates Old Trafford. At one stage, he conceded six boundaries in 24 legitimate deliveries. He also bowled a no-ball; only his fourth in Test cricket since 2013. His second spell - three overs for 16 runs - was, by the high standards he has set, uncharacteristically modest.
Usually so accurate, he struggled to maintain that probing line and length that has been the hallmark of English summers since… well, since the dawn of time, in cricket terms. When Anderson made his Test debut (May 2003), there had never been a professional T20 match, Concord was still in operation, Saddam Hussein was on the run and Lance Armstrong was dominating cycling. Naseem Shah, one of his counterparts in this match, was four months old.
At some stage, all those overs, all those miles, all those long spells to push for victory, to turn games that were slipping away, to offer his side control when nobody else could or just because every captain he's had in 10 years or more always relied on him, are going to start to show. He's bowled more deliveries than any other seamer in the history of Test cricket, after all.
Is it possible that moment was on the first day of this game?
Well, of course it's possible. It's worth repeating: he's 38. That's 10 years older than Mohammad Amir (at least, it's 10 years older than Amir's official birthdate) who has already decided to retire from Test cricket. At some stage, presumably some stage fairly soon, Anderson's magnificent career is going to come to an end.
But to conclude, on the basis of one modest spell, that Anderson is finished would be absurdly premature. For it was only one spell and it did contain only three boundaries. To make decisions on Anderson's future on such meagre evidence would be rash.
There were, it is true, another four fours in Anderson's first spell (5-2-16-0). But two of them were off the edge and, with just a little fortune, he could have taken a couple of wickets. Shan Masood played and missed three times against Anderson in that spell. On another occasion, he edged a boundary through the slips as he tried to withdraw his bat.
But there's never been much doubt about Anderson with the new ball. It's later, when he has to come back for second, third and fourth spells that the doubts are starting to grow. He didn't take a wicket in either of the second innings in which he bowled in the series against West Indies. He hasn't taken a second-innings five-for since December 2017 and twice in the last year he's been forced to pull out of games somewhere through injury. There's growing evidence to suggest he's finding it takes longer to recover between stints in the field. Even before this game started, it seemed unlikely he would play in the second Test and England look to utilise their depth to rest and rotate. It was a key point of difference between the sides in the victory over West Indies.
Babar Azam is relevant here, too. After weathering a hostile spell from Chris Woakes and Jofra Archer before lunch, Babar had settled and grown accustomed to the pace of the pitch when Anderson returned after lunch. And Babar really is very, very good. He provides no margin for error and can punish any semblance of looseness. He'll damage plenty more bowlers in his career. He took Anderson for three boundaries but, had Anderson bowled the same deliveries against, for example, Kraigg Brathwaite, he might well have conceded only four runs instead of 12.
Masood deserves some praise, too. He looked all at sea against Anderson the last time he played Test cricket in England. But he has worked hard - not least with Gary Palmer, the freelance batting coach who has also worked with England opener, Dom Sibley - and reinvented himself as a much improved batsman. Yes, he was beaten a few times. But he didn't follow or push at the ball. Instead he looked compact, patient and calm. However many runs Pakistan's middle-order contribute, they may well owe a few of them to Masood.
So, yes, there are, of course, legitimate questions to ask about Anderson's on-going selection. England are blessed with unusual depth in their seam bowling ranks at present and there are fine players - the likes of Craig Overton and Ollie Robinson - who would, in another age, be in the team. Right now, they can't even get in the squad. Neither Anderson or any of the other bowlers can afford a prolonged dip in performance. That's no bad thing.
And yes, it's possible Anderson concludes, in the coming days, weeks or months, he can no longer sustain the standards he has for so long and decides to call it a day. He looked frustrated here; chuntering, muttering and cursing his way through that second spell. It's entirely possible he was wondering why his body could no longer do what his mind told it. It happens to the best of them. Anyone who appreciates the craftsman he is should savour every moment of him in action at this stage. It can't go on forever.
But let's not rush to conclusions on one modest three-over spell. Batsmen are allowed poor games; keepers are allowed poor games; most other bowlers are allowed the odd off-colour game. Let's not use Anderson's impeccable record against him. He's earned the right to be judged on more than one three-over spell.