Mortality comes to man gradually and unwittingly, even though his recognition of it could be sudden. One day, combing the hair on his head takes a little longer for all the bare patches to cover.
One day he becomes a parent. One day, he realises there is social media and he does not understand it. One day, all his music becomes old.
The signs are different for an athlete because mortality has an entirely different meaning for him. One day, he is that bit slower. His warning signs of impending danger are less audible. But man or athlete, the message is the same: the end approaches.
This is the phase right now in the sporting life of Misbah-ul-Haq. On Wednesday, he leads Pakistan out against Australia for a 30th Test as captain. He is 40 now.
Though he has not looked especially out of touch, the last couple of months feel a little like that bald patch that refuses to stay hidden.
In the field – and this could just be the imagination – he has looked a touch older at midwicket, particularly when diving.
He has lost a lot of weight, when he probably did not need to; perhaps it is a sign that he is worried about his age.
He has also been run-out four times in his last few innings, which may not say anything without context, but you can see people might talk about that kind of thing and bring up his age.
Pakistan have five Tests this winter and then not another until after the World Cup. This stretch right now is where mortality is catching up with Misbah.
He may not be around after the World Cup. If his form does not return, he may not be around during it.
It is difficult to think he will be here for the next home season, when England and hopefully India arrive.
This could be the end. He is not immortal, not yet anyway. He has left an imprint in that this has been, inarguably, his era. Who could have even imagined that back in 2007?
If he leads all five Tests, he will move alongside Javed Miandad in having captained Pakistan in more Tests than anyone bar Imran Khan.
Let that fact sink in. In a country that has changed captains almost as many times as the number of years it has even been a country, to do it unchallenged for four years is a gargantuan achievement. If he somehow leads Pakistan to three wins from those five, or more, he could become the winningest Test captain in Pakistan’s history.
But a mere imprint does not, ultimately, say much. In their own ways, Salman Butt, Mohammad Asif and Mohammad Amir have also left theirs on Pakistan cricket.
No, every man wants to leave behind a reminder that, for a while, he did not just exist but that he meant something and that he fought off mortality.
Misbah will always have the England Test whitewash in the UAE in 2012, but it is his bearing as captain rather than the results that may end up meaning more.
When Pakistan was that man standing on a ledge threatening to jump, he was the guy in the next window calmly talking him out of it. That should not be mistaken for weak leadership: Misbah has exercised power rather than abuse it.
Here he stands now, aware of his own mortality. And he must be aware, for why else would he have stepped down as captain, even for just one dead-rubber ODI? That act in itself makes him unique. Nobody has ever willingly left the Pakistani leadership.
Now is also an opportunity. Pakistan’s modern record against Australia is miserable. No Pakistan captain has beaten Australia in a Test series since Salim Malik did so, 20 years ago. Only one has managed to not lose a Test.
But, even if Misbah is without half a team’s worth of frontline bowlers, his side is undefeated in a Test series in the UAE for four years. Australia could be on the verge of something special but this is an unfamiliar environment and they have not played a Test in nearly eight months.
Mortality does not stop men dreaming, and a series win against Australia? It may guarantee Misbah immortality.
Follow us on Twitter @SprtNationalUAE