The sporting life revolves around a repetitious and hypnotic soundtrack. Tick-tock goes the referee's wristwatch, the timer in boxing, the stopwatch in sprinting. The athlete is tuned to this ticking music but there is one clock he dislikes - the one which never stops while it counts down his career.
Athletes anyway don't age like us, their birth certificates are beautiful lies, for their body parts can feel distinctly older. In his 20s, a doctor told Diego Maradona that his scarred, battered knees belonged to an older man.
Tiger Woods is 38 but his wounded body and surgically-repaired back might argue that number. All those millions of swings, the hand-to-hand combat exercises, the weights, the runs in combat boots, the bulky physique, they wear away the body like sandpaper on wood. His greatness arrived from believing he was not like anyone else, yet, like everyone else, he is built of bone, cartilage, tendons and he hurts.
Pain is the athletes' friend and their enemy. There is the good pain of tough training and the bad pain of arriving injury. Pain transmits signals and, as Scott Barr, presently 17th on the Asian Tour Order of Merit, says: "You feel your body before it gets into serious trouble." It twinges, it aches, it throbs, it pinches.
Not everybody listens. Because athletes believe they must manage pain. Don't whine. Just put face mask over broken nose. Just swallow anti-inflammatories. Just inject cortisone. Just play.
A review of 15 studies by the PAIN journal in 2012 concluded that athletes "possessed higher pain tolerance" than normal people. They're used to it, they ignore it, they use ego to subdue it and drive to overcome it. It is at once heroic and insane.
And so Woods played because he wasn't just the man who reshaped how we viewed golf or whose length led to the redesign of courses. He was the rare jock as golfer, he just had to play, on a broken leg or with back spasms, for this is who he was to himself and us. Invincible and unstoppable.
There is a madness here, some gene of addiction and obsession which confounds ordinary folk and drives athletes to the impossible and the irrational. It is deeply coded into Woods' DNA, for whether it was winning or women or workouts, he couldn't recognise a stop sign. He had to chase Jack Nicklaus' 18 Majors even when he was hurt till he has arrived at this point where he has hurt his chase of Nicklaus.
The injured back - resulting in a missed Masters - matters for golf revolves around a rotating spine. "The back is the dynamic part of the swing," says Barr. "If it's hard to turn, you can't turn, and shots go everywhere." If you're everywhere, not on the fairway, not near enough to a pin, you can't regularly win. And so Woods, the man who changed golf, must change himself.