SERENA Williams makes jokes about arthritis these days, about the good-time girl who has become so staid that she often fancies a nanna nap, and so dull that sometimes she even bores herself. But the funster is still there, somewhere, surely? ''Oh, totally, totally,'' she insists. ''It completely lurks within.''
The big change in Serena Williams dates to June, 2011, and her return from the pulmonary embolism that had threatened her life. At first, those in tennis noted a more thoughtful, pleasant character, even in defeat, but waited to see if the transformation would be sustained. Apparently, it has been. In turn, she talks of feeling rejuvenated, excited just to be playing, appreciative and thankful that she is.
''I'm 31, and I'm just trying to get more serious about my life, and what I want from my future, and not only tennis-wise but also spiritually, emotionally and stuff like that,'' says one of the all-time greats of the women's game. ''You get questions in your head and it's like, 'Do I really want this'? You have to make some big decisions.''
Any that she can talk about? ''Not really. I just think I'm a little bit more relaxed, a little bit more laid-back, and a little bit more chill.''
Happy, too, with French coach and beau Patrick Mouratoglou, content with both her life and career. ''I am. I'm really focused on my tennis,'' she says. ''It's one of the priorities in my life, and it always has been. I've always done pretty decent, so it's always been a big priority to me, but it is even more so now than before, and I think that's made a big difference in my tennis career. Like, I don't hang out as much, but I didn't do it on purpose, it just kind of happened with extra work and extra this and extra that.''
Not coincidentally, the latest 18-month phase of a stop-start career has delivered 10 titles, including two of the past four majors, Olympic gold in extraordinarily emphatic fashion, and the year-end WTA Championship. Although Williams will reclaim the No.1 ranking if she reaches the final at Melbourne Park on Saturday week, and would be the oldest player ever to reign, the number that interests her (her astonishing 3.3 million Twitter followers belonging to another category altogether) more relates to major championships.
The Australian Open will be her 50th, and she is fifth on the all-time list with 15 titles, but laughs an emphatic ''no!'' when asked if anyone can break Margaret Court's 40-year-old record of 24.
''I think one day someone will. Will it be me? I don't think so.'' But do the maths, we suggest. Three slams a year for the next three years (perhaps not the French Open, that remains her hardest assignment) and, well … voila. ''Rrrreeaally,'' she drawls, rather theatrically, out of the corner of her mouth. ''Oh god. Exactly. It would be really difficult.''
So what about Steffi? Is Graf catchable? ''What is Steffi? 22? Oh my god. I have to get to Chris [Evert] first, and Martina [Navratilova], before I can even think about anyone else. And Margaret's 24, right? Oh, my gosh.''
Yet who could count against Williams doing more great things? Injuries, illness and personal issues have meant that, in thoroughbred terms, she is what one commentator aptly called ''lightly raced''; her monstrous serve, forehand, and killer competitive instincts remain. Indeed, her perusal of YouTube highlights suggest to Williams that she is playing some career-best tennis right now. Which is saying something.
Her serve is rated by John McEnroe as the best in the history of women's tennis, and by Mouratoglou as easily the most natural shot in her repertoire. ''It's completely fluid, and with her wrist, she has the ability to decide which serve she's gonna hit at the last moment, so that makes it not impossible … not impossible, [but] very difficult to read,'' he says.
The 58-4 record she compiled in 2012 included just one loss after the watershed French Open in May when, slightly jaded by the gloriousness of the early northern summer, she faltered against Angelique Kerber in Cincinnati. She is a combined 21-3 against Victoria Azarenka and Maria Sharapova - the two players numerically above her - and has a higher overall winning percentage at the grand slams than regular events. Unquestionably, when fit and at the top of her game, no one can stop her.
''I've always thought if I've played my best it's really difficult for anyone to beat me,'' she concedes, trying her best to be modest. ''That being said, I don't want to sound like I'm full of myself or anything, but I think I have a pretty good game for now. In the Olympics, I pretty much played my best, or close to it. Obviously, things will change in the future but, for now, I'm still doing pretty well.''
No kidding. Williams resumed in 2013 - with a 47th career title at the Brisbane International - as she ended 2012 at the WTA Championships, yet the majors are really what she counts now, and Mouratoglou has no idea if fingers and toes will suffice. ''How many [grand slams]? I have no idea,'' he said. ''Since she's healthy and she keeps having the motivation to work every day and improve, I think she can win [for] many years.
''She's very motivated, that's maybe what is the most impressive with her, because being 31, 15 grand slams, after being five times No.1, keeping this will to win and this will to go on court and practise every day in order to keep winning grand slams, I think this is really what makes the difference. For me, on the men's tour [it] is the same with Roger [Federer], they're very special for that. Some win one grand slam and they're happy all their life.''
But not Williams. Oh no. Even if what she has achieved so far simultaneously validates the Williams family credo of limiting match schedules while pursuing other interests and a healthy life balance, and prompts the question of how many more she would have won had her schedule been busier. The second is not a cause for regret so much as a query she coyly turns back on the interviewer.
''Would I [have won more]? she counters. ''Or would I have won less, 'cos I would have been tired or burnt out? It's a good question to ponder.''
Well, does she think she would even be playing now had she been more active in past years? ''Exactly. Would I still be playing now? I don't know. Am I playing now because I haven't played all the time and because I've had some unfortunate injuries? Maybe. Hmmmm.''
And yet, this time last year, Williams declared she was not in love with tennis, but had only stuck with it because she could not do without it. Asked when the passion was rekindled, she could not pinpoint an exact moment, but used the example of a recent match in which she walked out feeling excited just to be there.
As she speaks of her so-called ''reinvigoration'', Mouratoglou walks past, and warm smiles are exchanged in a wordless conversation.
''I honestly think the injury really took a toll on me, and everything I experienced makes me just so happy to be on the court,'' says Williams.
Indeed, she has described her acceptance of Mouratoglou's offer of a practice court at his academy after her unthinkable first-round loss to Virginie Razzano at Roland Garros last year as her Sliding Doors moment, in reference to the Gwyneth Paltrow movie about the potentially life-changing consequences of a missed train.
Does she wonder where an alternative journey might have carried her? ''It's so funny, I saw the movie a few days after that, and I was like 'wow'!'' she says.
''I don't know. Obviously I would be playing. I think I would be doing well. I mean, I think my game is suited to doing well, really, but I think Patrick is a good addition. It would be interesting to see which way it would have gone.''
The biggest thing Mouratoglou has brought to the table is too tough to answer, she insists. ''Honestly, it is so difficult to tell right now. There's so much that he's brought, but what is the most thing that he's brought? I don't know. I'm just really calm, but I've been working on being calm and more consistent, so I think those are some things, and confidence as well.''
A little maturity and a fair bit more perspective seem to have come of their own accord, and her reliably warm welcome at Melbourne Park compares favourably with what she concedes have sometimes been less enthusiastic receptions elsewhere. Yet if a famous funster lurks within the newly demure Serena Williams, the enduring superstar of women's tennis remains a commanding presence that it is hard to imagine the game without.