What's in a number? Plenty if the digits in question are the mysteriously meaningful 4 and 2.
For instance, statistics show the average age of overseas visitors to the Sevens is 42. So it's surely no coincidence that in Douglas Adams' eternally thought-provoking sci-fi comedy/philosophy classic, The Hitchhiker's Guide to the Galaxy, "the answer to life, the universe and everything" is 42.
One of the 42-year-old brigade, making another return to our city for the rugby and socialising event of the year, is Dirk Scott. His father was a Hong Kong policeman, so Scott grew up here, attending the very first Hong Kong Sevens in 1976 as a young lad on his dad's shoulders. During his time here, he also used to play with the Kai Tak Tigers.
Now the former Cathay Pacific station manager and corporate safety manager is the GM for operations with Menzies Aviation at Sydney Airport and he's very much looking forward to a reunion with mates from Sai Kung and DeA Tigers.
While not an ever-present at the tournament over the years, he has racked up an impressive attendance tally, claiming around 20.
"I missed all of the 1980s Sevens as I was at boarding school in Scotland," says Scott. "Then I lived back here and in Macau for a few years. What I love about the Sevens is that even if you didn't grow up in Hong Kong like me, you'll have connections. Everyone runs into someone they know - someone they've worked with, someone from school or their home town. Hong Kong is a vast international city, but it's still a village with a strong sense of community. Everyone is welcomed here."
The number 42 crops up in other areas, too. Many Sevens tourists are stunned to learn that beyond the bright neon lights and shimmering harbour vistas, a staggering 42 per cent of Hong Kong is designated as country park.
And style-conscious Hongkongers may be intrigued to consider how many queens of fashion take a size 42 shoe, (US size 10.5/11), from Audrey Hepburn and Jackie Kennedy Onassis to modern-day icons icons Paris Hilton, Kate Winslet, Tyra Banks, Geena Davis, Meg Ryan, Uma Thurman and Michelle Obama.
However, despite Adams' claims, 42 is not the only number of importance - at least in the galaxy of Sevens demographics.
Try these for size: the average Sevens visitor's personal income is US$121,293. Most of them fly in from the UK, Australia and the US. And 91 per cent of them come for vacation, 9 per cent for business.
The tournament last year generated 255 hours of television in 254 million homes in 136 countries, 33 more than in 2011. Apart from 40,000 people in the stadium, two million people in Hong Kong (population seven million) watched it last year, so the numbers say.
That's plenty for the beancounters and sociologists to ponder but for most people here this week there's one easy rebuttal to Hitchhikers, Galaxies and the magic power of 42. They would say the answer to rugby, life, entertainment, the universe and everything is, of course, seven.
No matter what your age.