As Diane Sawyer pointed out in the introduction to the groundbreaking interview with the person who used to be Bruce Jenner, how you recognised the personality was an indication of which side of the generational divide you stood on.
For someone born in the 1950 and '60s, Jenner was the swashbuckling sportsman who had won the gold in the decathlon against a Soviet hero at the Summer Olympics in Montreal in 1976. He had been declared the greatest athlete in the world.
For others, however, Jenner was the somewhat elusive, goofy but loving dad in that mother of all reality shows, Keeping Up with the Kardashians, on which was predicated a billion-dollar industry of American consumerism.
But, of course, however larger than life both personas appear, they pale in significance before Jenner's latest persona: the one that this generation of children will know as Caitlyn Jenner, the female 65-year-old media sensation that Jenner has transitioned into on primetime television.
"Where were you when Kennedy was shot?" might well be replaced with "Where were you when Bruce transitioned to Caitlyn?" Like many others interested in popular culture, gender studies and people-watching, the Caitlyn story has riveted me.
But unlike many others, I had not watched a single episode of the Kardashian reality show nor been particularly aware of Jenner's sports legend before I set eyes on the tall, intriguingly androgynous, handsome person in the Sawyer interview. It occurred to me that had I not been alerted by the media hype and sensation, I could have gone right past the now irrelevant account of his masculine existence and met him as Caitlyn - the svelte, corset-clad bombshell on the cover of this month's Vanity Fair.
Perhaps the last frontier of human sexuality is gender identification. As Jenner says, he knew he was a woman ever since he was a child. That he had to live a lie for 65 years and while doing so, manage to not only achieve the highest pinnacle of sporting excellence, but also keep his dignity while participating in a schlock TV enterprise, is a measure of his profound strength of character and emotional intelligence. "If all that I have done - the TV show, the Olympic victories, everything, has given me the platform to make a change for the good - then it's been worth it," Jenner had said to Sawyer, who could barely contain her astonishment at what was being revealed.
Successful sports athletes and showbiz personalities are least expected to upset the status quo, especially while flying in the face of public norm. To do so is to risk losing it all and worse, being faced with hostility and ridicule.
And yet Jenner did so. She did so because, she says, it was not possible to carry on one more day longer living a lie. She did so because the years were slipping by and she did not want to think in her dying moments that she "blew her life away".
So, this week, one of the world's greatest athletes and a showbiz superstar, the father of many children and the man who had married three women - decided to announce his female identity. "Call Me Caitlyn" was his first handshake with the world.
It is an epochal moment in human evolution. Yes, there have been many transgender people before and many who will follow, but none so arresting and thought provoking as the legendary, muscle-bound male sportsman who became Caitlyn before our very eyes!