I keep coming back to Silicon Valley in California because it is such an instructive place to think about how businesses are created - and maybe thrive.
For decades now, a stream of start-up companies have grown big and influential in the Valley, built around the silicon chip and the new economy created by computing.
Clustered around all the skills a start-up business needs - the backers, advisers, lawyers, and venture capitalists - the little towns that make up most of the Valley are a magnet for the brightest minds from all over the world, drawn by instinct to a place where things happen.
Fascinating, therefore, to stumble on a building which is a microcosm of Silicon Valley as a whole.
It's run by Saeed Amidi, whose family fled from the Iranian revolution in the 1970s. He went to business college in the Valley and was shocked when his father suggested that he should start working for a living.
The family had opened a Persian rug shop in the main street in the rich little city of Palo Alto, just down the road from Stanford University and the vast concentration of wealth controlled by the venture capitalists in Sand Hill Road.
The shop, Medallion Rugs, is still there. It's a good place to run into start-up business people who have just made a fortune by floating their new companies.
They need floor coverings for their new house - one of the things that newly wealthy people buy.
Saeed Amidi got on with starting his own businesses: real estate, investment, and a water bottling company.
Eventually he bought the nondescript premises further up the street that he was running his operations from - 165 University Avenue.
When I first saw it - something like 10 years ago - it still had a sticker on the front from a recent tenant: Google.
Before Google, it was the offices of the global computer peripheral specialists Logitech, originally from Switzerland, and famous still for their webcams, keyboards and mice.
Successful start-ups don't stay very long at 165 University Avenue. The premises, laid out round an upper floor courtyard, are fine when you have only 20 employees but get crowded if you grow to 60, which is what new businesses tend to do, fast.
After Google moved out, the internet payments company Paypal and the mobile phones developer Danger came along. Both made their founders and backers hundreds of millions of dollars a few years after they moved on from 165 University Avenue, by selling themselves to bigger companies.
And the savvy landlord Saeed Amidi insisted on taking a small stake in Paypal along with the rent.
With a record of canny investment behind him, he's now leasing office space to even more start-ups in larger premises nearby, hoping that the luck of 165 University Avenue can rub off on a new generation of entrepreneurs.
When it comes to starting a business, you can't neglect the influence of luck.
Listen to In at the Start, Peter Day's report on 165 University Avenue for In Business on BBC Radio 4.