"Only the elite of the elite can change the way their sport is played. Think of Stephen Curry's influence over modern basketball and its fixation with outside shooting. Or Tiger Woods' revolutionary impact on golf. Add Williams to the mix."
The fact that two girls from humble beginnings in Compton, California, would come to dominate tennis at the highest level for years is remarkable.
Experts estimate Serena will retire with record earnings. She earned $450 million from prize money and sponsorships, 40 per cent more than any other female athlete ever.
More than money, though, it's Serena's message about juggling parenthood and a demanding job that has made an impression on many people, including me.
Serena said she wants to grow her family and evolve as a fashion maker, venture capitalist and much more. She announced her retirement in an interview in Vogue magazine:
"Believe me, I never wanted to have to choose between tennis and a family. I don't think it's fair. If I were a guy, I wouldn't be writing this because I'd be out there playing and winning while my wife was doing the physical labour of expanding our family. Maybe I'd be more of a Tom Brady if I had that opportunity."
Some sports websites claimed she 'took a dig' at NFL quarterback Tom Brady.
One commentator said Serena using Brady as an example to highlight the difference between being a male and a female athlete in their 40s was ill-advised.
Rather than view Serena's words as misguided, why not see them as a call to reimagine motherhood as transformational rather than limiting?
In navigating the nuances of her decision, the tennis great invites us to consider the constraints and possibilities of parenthood.
We need to encourage and expect that men will take as much parental leave as women, that any parent will step up to care for a sick child, that any parent can follow their career aspirations because they have back-up from a partner, and/or from family, friends and their community.
Serena wrote, "A lot of people don't realise that I was two months pregnant when I won the Australian Open in 2017. But I'm turning 41 this month, and something's got to give."
When that something gives, who makes the sacrifice? Men? Women? Do they split home and childcare 50/50, 80/20, or a percentage in between?
If he chooses parenthood, I want my son to have choices about working and staying home to raise a child.
He could follow in his late father's footsteps and become the primary caregiver for the first few years, changing nappies, feeding babies and toddlers, and getting into the sandpit to play. More opportunities for women mean more opportunities for their partners, too.
We typically hear men say they're taking a break for the family following a health issue or scandal. Women taking time off for family is a given; no special circumstance required.
How many All Blacks get asked who is looking after their children? Even in today's diverse, rainbow world, we make assumptions about gender roles and division of labour. We applaud men such as Black Caps bowler Trent Boult, whom New Zealand Cricket agreed to release from his central contract in a move reported as a "shock announcement".
What is the shock? That Boult is bowing out of fulltime cricket, or that as a man, he's leaving a demanding job that requires international travel to spend more time at home with his young family?
You don't have to be a tennis fan to appreciate Serena's legendary career or her difficult decision to transition to a new life off the tournament circuit.
I hope her words will help change the way we think about parenting and about reinventing ourselves.
Serena quoted her sister Venus, saying, "When someone out there says you can't do something, it is because they can't do it. But I did do it. And so can you."
Dawn Picken has written for NZME since 2014 after a career in television news and marketing in the United States. Picken teaches in the business department of Toi Ohomai, where she shares stories of leadership and change.
