Most everyone fantasizes about holding back the ineluctable advance of time, but only force-of-nature type personalities can convince themselves they have a shot at succeeding.
And the Williams sisters, formerly of Compton, Calif., are nothing if not dynamic natural phenomena.
Venus, now 34, and little sister Serena, 32 (as she semi-tartly reminded a reporter earlier this week who referred to her being 33) will meet in the semi-final of the Rogers Cup in Montreal on Saturday.
That's all well and good, but no one should mistake this season or the 26th head-to-head meeting of their illustrious careers – and only the second since 2009 – as some sort of coda.
Neither has any intention of shelving her racquet any time soon.
"I don't want to let go. I won't let go," laughed the top-seeded Serena Williams said after a come-back 4-6, 7-5, 7-5 victory over Danish former world No. 1 Caroline Wozniacki.
Venus Williams, another former No. 1 who has struggled with fitness and form – in 2011 she was diagnosed with Sjogren's syndrome, a rare autoimmune condition whose symptoms include chronic fatigue and joint pain – sounded a similar note.
The competitive fires still flicker brightly, but in Venus's case it's also a deeply personal challenge.
"I think I'm playing for my own redemption, just to prove to myself that I can be strong. I play because I love it and I want to win titles, but I also play for that. I don't want to lay down, let anything run me over, whatever it is," she said after a tough 4-6, 6-2, 6-3 triumph over Carla Suarez Navarro of Spain. "Now I got to play as long as I can because of that. So young V, when she first played her first Rogers Cup would have thought 'you shouldn't be playing at this stage'. But old V says, young V, you're an idiot."
With age comes perspective; in that sense, the Williamses are cognizant of the impact each has had on the sport.
Black players like promising Americans Madison Keys and Sloane Stephens, and 17-year-old Canadian Françoise Abanda are living reminders of their legacy; all three played in Montreal this week.
"I think having been pretty much the first African-Americans to do well, then to see all the African-Americans, even some Canadians here playing really well, it makes me feel really good," Serena Williams said.
Added Venus: "at the end of the day life is about what you can give, not really about what you can get. I think in a lot of ways the work that we've put in on the court has been able to give so much to so many different people in so many different ways. That was a result that we, as sisters or as a family, never saw coming."
As a footnote, neither woman thought she would still be touring the world with their tennis bag in tow at this stage of their lives; it's true they have myriad off-court interests (they bought a minority stake in the NFL's Miami Dolphins in 2009), but the allure of the court abides.
So here they are in Canada, Serena vying to defend the title she won in Toronto last year, Venus simply trying to capitalize on the first working visit to Montreal of her 19-year career.
Though the elder Williams said – almost wistfully – that she prefers playing Serena in the finals of tournaments (this has happened 11 times), the semi will do nicely.
And if Serena has a decided 15-10 edge in the head-to-head battle and the cachet of the world's top ranking, she takes nothing for granted in their on-court sibling rivalry.
"I definitely don't like playing her. I think I've lost to her more than anyone on tour so ..." she said. "Definitely not a fun match."
Serena talked about the possibility of facing her sister without knowing the outcome of the match with Suarez Navarro, and if she expressed a desire to hang around among sisters on Friday evening, Venus hinted that it probably wasn't in the cards.
"I'm actually going to dance a little bit. I actually am," she said. "It's very relaxing for me. I love to dance."
Asked to elaborate, she said "not in a club. No, I just do a little jazz and a little ballet. I'm not great, but I love to dance. I'll just dance a little and see what happens."
Pressed further by an inquisitive reporter, Williams just smiled.
"I can't get into the details," she said, "It's like Fame."
It's surely a coincidence Williams would reference a film and musical whose most memorable tune is I'm Gonna Live Forever.