The first thing to know about San Francisco is it's beautiful. The second thing to know about San Francisco is it's full of Crazies. But nice Crazies.
These two things are indispensable to the city. They call Los Angeles the entertainment capital of the world but San Francisco seems much more like the American West's cultural capital.
It's impossible not to stumble across galleries, museums and places sacred to subcultures like the Beat Generation and its countercultural spin-offs of the 1960s.
The city has a long, proud history of subversion, innovation and agitation. It's
the hub of the Bay Area, a place today redefining the world, setting every major technological trend.
It's probably a stretch to apply the old "fine line between genius and madness" as a metaphor for the people of San Fran. But even the street people here seem innovative and entrepreneurial.
Out for a walk one Friday night, in just a few blocks I am offered coke, weed, the Street Sheet newspaper and even advice on how to order taxis and which bars to go to.
Some of the Crazies don't just talk to themselves - they talk to themselves and their three imaginary friends all at the same time, in meandering, broad sweeps of the imagination.
It's at times an indictment of America's Calvinist dismissal of social democracy in favour of self-reliance, but if you're going to be down and out anywhere in the US, this is probably the best city to be in.
Jack Kerouac would still love it, and probably recognise much of the city he helped make countercultural capital of the world.
Near the Beat Museum and City Lights bookstore a block or two from Chinatown, an alley re-named in Kerouac's honour is plastered with bright murals and tributes to great writers.
About 5km southwest, we take a trip with Urban Hiker San Francisco in the vibrant Castro neighbourhood.
It's a prominent centre of local gay culture and is close to several big urban parks, including Twin Peak Summit, where bush and pathways surround a huge TV tower.
East of The Castro, the Mission District heaves with colourful restaurants and murals celebrating the city's progressive social movements as well as local heroes such as the San Francisco Giants baseball team.
We join a food tour around the Mission with Ida, our lively guide from Avital Tours, stopping to snack at several local restaurants. The area pivots around Mission San Francisco de Asis, or Mission Dolores, built in 1776 and San Francisco's oldest surviving building.
Nearby, in big, sloping Mission Dolores Park overlooking San Francisco's gorgeous skyline, folk of all races and persuasions enjoy themselves. They're allowed to drink and play football and, in one case, even pitch a tent without being nagged or nannied or regulated, as would happen in most Antipodean cities.
It's a breathtaking city. It feels like the epitome of American optimism, and for
Flattened barely a century ago, smashed again in the 1989 earthquake, this is the city that refuses to take rubbish from anyone. Reactionaries, homophobes, plate tectonics, rival cities' sports teams - none has been a match for San Francisco.