On Tuesdays and Thursdays, Herbert Hamrol works at the local supermarket near his home in Daly City, on the outskirts of San Francisco, as he has done for about 30 years now.
Quake survivor Herbie Hamrol still works in a supermarket, aged 103
Nothing remarkable in that - until you learn that Herbie is 103 years old and one of the few living survivors of the Great San Francisco Earthquake and fire of 1906.
On Tuesday, Herbie will gather with others at Lotta's Fountain, the city's oldest surviving monument and a focal point during the disaster as a meeting place and bulletin board for families and survivors.
Every year, on the anniversary of the quake, which struck shortly after 0500 on 18 April, 1906, this has been the centre of commemoration.
But the survivors grow inevitably fewer with each year.
In 2005, Herbie was there with fellow earthquake veteran, Anita Caruso. Sadly, Anita, died just a month ago, at the age of 102.
Had she lived, she would have told how she and her family camped out in Golden Gate Park, while the flames ripped the city apart around them.
Herbie can still remember being carried down the stairs of the Hamrol house, south of Market Street, in his mother's arms, and how his sister thought it a great adventure to live under canvas when their home was destroyed.
And there are the memories bequeathed to the present from the past, such as those of railway worker, Clarence Judson, taking an early-morning dip on Ocean Beach, virtually over the San Andreas Fault, when the earthquake struck.
"The motion of the quake was like the waves of the ocean, but swift and choppy, with a kind of grinding noise," he said.
"I tried to run to where my clothes were - then I thought of lightning, as the beach was full of phosphorus. Every step I took left a brilliant, incandescent streak. I began to think the world was coming to an end."
Many San Franciscans today have stories of more recent seismic activity.
In 1989 an earthquake struck again, severely damaging freeways and the Bay Bridge and taking the lives of more than 60 people in the Bay Area.
"You know you're in an earthquake," one survivor told me. "It's like nothing else - it's awesome."
A 1989 earthquake claimed the lives of more than 60 people
The common theme in memories is the sound - that grinding of the tectonic plates, followed by a silence and then, bizarrely, the sound of the city's church bells - a cacophony of jangling as the earth moves.
The 1989 disaster was a wake-up call - but it was not "the Big One".
San Francisco is a city in denial. It has been so for 100 years.
In 1906, photographs of earthquake damage were touched up to mask the scale of destruction and the size of the death toll was played down; after all, investment must be brought back to the city.
Within weeks the cable cars were running and rebuilding took place with phenomenal speed - so fast, some say, that lessons were not learned from the past.
Wooden buildings were erected again, too close together, and new buildings went up on reclaimed land, which had shown itself in 1906 to be the most vulnerable.
Investment and big business did return to San Francisco. And the denial continues.
Everyone knows "the Big One" is coming. With earthquakes, if you are on the fault line, it's not if, it's when.
And the 1989 earthquake - for all the death and destruction it caused - was 1/32 the power of the 1906 event. The next one could be in a year, or 10 years - or it could be tonight. But whenever, it will come.
It is interesting to talk to Californians about their attitudes to this, because they live here in the clear knowledge that they are sitting on a seismological time bomb.
"So why are we having this conversation here at all, in this place, given its history, and given what we know to be its future?" I asked one native San Franciscan.
His reply reflected the stoical philosophy I found in everyone I spoke to in northern California: "San Francisco is a great, beautiful city. It's a terrific place to live. And, hey! You're going to die somewhere anyway, aren't you?"
Meanwhile, Herbie Hamrol works in his Daly City supermarket, and takes part in earthquake commemorations as and when they happen.
"Herbie? Oh, he's a national treasure," more than one Californian tells me. And so he is.
And there seems no reason to suppose that he will not be around for future remembrances beyond the 2006 party. Herbie's sister lived to be 105.
I suppose if you survive something as big as the San Francisco Earthquake of 1906, there is not much else life can throw at you.
The Frisco Quake was presented by Sean Street, professor of radio at Bournemouth Media School, Bournemouth University, on BBC Radio 4 on 12 April 2006.