November 14, 2002:

San Francisco MUNI bus, 5 Fulton line, inbound, about 8am on a workday.

Commuters at Masonic wait near a neighborhood liquor store. Everyone looks at their shoes, their newspapers, their watches. Anything but each other. It's like the inside of a crowded elevator.

In California strangers don't talk to each other in public. It's different on the East Coast, where something of the old-world village culture persists, maybe. In California, if a stranger says hello you think it's Charles Manson and you cross the street as quickly as possible.

Masonic is already almost half-way along the route, and the people are packed to a degree that seems unhealthy. You edge between them shoulder-first, sideways, making yourself as thin as possible. With struggle you take a standing position with both hands on the overhead bar, your canvas book bag between your feet on the floor. It's so crowded that it takes longer to settle the oncoming passengers than it does to drive to the next stop.

Everyone smells: shampoo, deodorant, cigarettes. No-one is happy. Everyone strains not to fall into their neighbor. Potholes send tremors through the mass. Turning corners tightens our lips and turns our knuckles white.

People cope via individual variations on two basic themes: disassociation, or amusement. The most-disassociated are those with Walkmen, as if a private soundtrack means a personal movie. Others are simply grouchy, as though projecting a "back off or die" attitude could create the space for others to back off into. The amused group can be especially annoying if you're affecting one of the other strategies.

Professional-looking young African-American woman in a tasteful blue business suit. Early thirties, cell phone, manicure, perfume. Sparkling brown eyes that twinkle with mischievous humor; leather business heels that must be hell right now. She's been looking at you for some moments.

"It's our morning physics lesson," she says, eyes twinkling.

When someone talks to you on the bus, you have no option of retreat. There's no street to cross, quickly or otherwise. It's funny sometimes watching people's reactions, for instance when they're clearly alarmed, or committed to their "back off or die" stance no matter how badly it's just failed.

No idea what she's on about. But, after a moment of hesitation, you decide you'd may as well be polite about it. It's not like you're going anywhere. And anyway her tone is mischievous, inviting cooperation. She doesn't look like the Manson family. You raise one eyebrow, like the straight man in a comedy act, implying, "Oh?"

With a resigned-but-amused tone she hits the punchline, as another pothole sends you all lurching from side-to-side. "Sometimes we act like waves," she says, "sometimes we act like particles."

A slow smile spreads and deepens. That's a good joke. It's really seriously good. Actually - it's really seriously a good joke. Your grin expresses two flavors of appreciation: first, at the ingeniousness of the line, second, over her generosity in sharing it with you. Your smile lasts all the way to Leavenworth Street, which has just never struck you as that funny a place.