Venus Williams played 11 matches of tennis in all of 2011, has had six months out as she comes to terms with an illness, and is now in the last 16 of a major event. How?
Her comeback run in Miami, during which she has dumped out the Wimbledon champion and world number three Petra Kvitova, has been described in some quarters as 'inspirational'.
It's certainly a remarkable story. Venus, now 31 years old, had been struggling with injury and fatigue for some time.
After a schedule in 2011 that Tramlines would generously term 'limited', Venus turned up for the US Open, won her first-round match then withdrew, citing Sjogren's syndrome, an incurable auto-immune disease.
The symptoms of fatigue, swollen joints, dry eyes, dry mouth and heavy limbs vary in intensity from case to case, and while they can be managed, they are hardly the ideal starting block from which to compete with younger, injury-free players at the cutting edge of elite tennis.
And yet here she was, back into the rhythm of tournament play, grafting her way through the tournament with matches every other day. Twice in a row she has been taken to three sets, and twice she has come through — the first time against Kvitova a bulldozing 6-0, and in the second instance a dogged 7-6 triumph against Canadian world number 65 Aleksandra Wozniak.
The psychological hold Venus has steadily built up over the years evidently still exists — how else to explain hitting 70 unforced errors in a single match against Wozniak and still wrapping up victory?
But then that's testament to a career in which Williams has won seven Grand Slams, held the number one ranking and taken in numerous victories which were masterclasses of vicious, brutal hitting.
Perhaps it is a poor reflection on women's tennis that a generation of players have struggled to take the game on from the era of the Williams sisters — if they have managed it, then they have not been able to sustain it for any length of time.
These days there are players on the tour who were born after Venus turned professional at the end of 1994. When Venus is still finding a way to win, that's how legends are built.
The doubters said Venus and Serena Williams would be gone by now, and yet here they both are.
Of course the pair have at different times and for different reasons spent stretches away from the court, and they have indulged other interests outside of the sport (most notably fashion). But that seems to strengthen their love of the sport rather than distract from and diminish it. Tennis is a choice they have to make, and now, when their tennis contemporaries are for the most part retired, they still make that choice.
And they choose tennis nowadays without the financial imperatives, or the need their father imbued in them as youngsters to make something of themselves. They are made — their lives are secure. Moreover, if the Williams sisters were to compile a pros and cons list about whether to compete, their health would surely be reason against the tennis treadmill.
While Venus lives with Sjogren's syndrome, Serena has had to recover from blood clots in her lungs, something that could so easily have killed her.
Since missing a year of tennis to recover, Serena has reached the final of the US Open and is still a contender for the sport's biggest tournaments.
Health permitting, they'll return to the UK for a double (or should that be quadruple?) attack on Wimbledon this year — first for the season's third Grand Slam, then weeks later for the Olympics, which will be held on the famous grass courts.
How many times thereafter we see them at Wimbledon, or indeed on tour, remains to be seen. They are both in their thirties now, and they have nothing to prove.
They are far from perfect, and their conduct has not always been exemplary. But they have been a credit to the game, and as they solider on in Miami, and throughout the rest of their careers, you should enjoy them while you can.
SPOT THE DIFFERENCE OF THE WEEK: One is a cartoon character in a long-running American sitcom, while the other is Germany's Mona Barthel as she serves in Miami. But there's just no telling which is which.
TWEET OF THE WEEK: "Having some quiet time.. Just me, myself, and toilet. Nothing else.." — well, except for Twitter. And therefore everyone else. Thanks for sharing, Ivo Karlovic.
COMING UP: Miami continues. You can watch the women's side LIVE on British Eurosport (or get yourself the Eurosport Player) — while for the men's side we're bringing you match-by-match live text commentary.