It was on an uptown bus in Manhattan, early winter, a darkening, wet evening, when the scrunkled, middle-aged man with the startled stare got on the bus around East 49th Street.
He sat there, alarmed, staring around at the peak hour commuters surrounding him, his eyes like frisbees.
As the bus approached 57th Street, another passenger pulled the cord to get off. The bell rang, "DING!"
The scrunkled man started urgently, and he cried out: "Saint Louis! Anyone for Saint Louis?..."
Mastery of travel is a process of mastering local public transport. Not just the timetables and the stops, but also the etiquette.
In New York, it means, as much as anything else, accepting the foibles of fellow passengers, all of whom are pretending they're the only ones on the bus or the subway.
One New Yorker tells the story of the commuter attempting to halt a crowded subway train during morning peak hour.
Running down the stairs, the commuter threw his arm and briefcase through the closing train door, hoping this would be enough to force the door to reopen.
But his New Yorker's wrist must have been slight, for the door sensed it had shut, and the train pulled away.
His briefcase trapped inside the train, the commuter broke into a trot as the train accelerated. The alternative was dropping the briefcase inside the train and withdrawing the wrist to safety. Clearly unacceptable.
The concrete wall at the end of the platform approaching rapidly, commuters inside the crowded train, all of them until then affecting not to notice, began to stir.
Seeing how close the wall was coming, one of them used his free arm to try to force open the door.
It wouldn't budge. So he dropped his own briefcase, put a foot in the door, and used both hands to prise just enough gap that the commuter, now-running hectic along the platform outside, could extract his briefcase through the door.
Just in time.
Don't be put off by wide eyed former train conductors, or sprinting commuters. In New York, in one way or another, these situations are the norm.
Every place has its idiosyncracies.
Take getting off the bus in San Francisco.
Having pulled the cord to get the bus to stop, this traveller stood at the top of the middle stairwell, the exit point, waiting for the door to open.
It didn't. We waited, a fear rising inside that it would never open and we'd be kidnapped to the next stop.
We heard the bus driver shouting to us, but we were oblivious to what he was saying, petrified by fear that, as out-of-towners, we had no idea what to do next.
Only after several shouts did we realise what he was saying: "Step down, sir".
We had no idea what he meant, our judgement distorted by confusion. We started towards the front door -- the embarking door -- but the driver repeated, "Step down, sir".
Clueless, we headed back again. Bus drivers get very finicky about which door you use. We'd seen several in our few days in San Francisco become strident with passengers seeking to use the wrong door.
We stood again at the top of the middle stairwell; again, the door did not open.
Other passengers joined in: "Step down, sir". It was a fragmented chorus. We flushed with embarrassment; we felt the right goose: couldn't even get off a bus.
Then abruptly, in one of those epiphanic moments, we stepped onto the first step in the stairwell. And the door opened.
In San Francisco, you must step into the stairwell for the door to sense your presence, and it will open.
In contrast, we are used to signs urging us to keep out of the stairwell, to stay clear of opening doors.
But from that moment, and from the point at which we realised that a basic bus ticket in San Francisco gives us 90 minutes of travel on any bus, we became masters of the local bus system.
Mastery of public transport is the lifeblood of local travel. You can be as clever as you like at airplane queues, customs and immigration, but unless you know how to ride the buses, trains and ferries, you're stuck at the airport.
Each place has its peculiarities. European cities are infamous for their earthy locals.
Another traveller made her first friend in Paris through a crowded Metro in evening peak hour, although they never spoke or exchanged pleasantries.
Crammed against her in the carriage, two locals were overpowering in their body odour.
It was mid-summer, and the traveller began to swoon. Her eyes rolling, they met those of a Parisian commuter, a small, ordinary man, crammed on the other side of the stench, who rolled his eyes back.
The most effective communication uses no words. She knew what he meant and, in that moment, they bonded, then parted.
Two days later, the traveller was making her way through the labrynthine tunnels that join the various lines and stations of the Paris Metro, and there he was again.
As they passed, their eyes met, quizzically at first. Then it dawned on each of them where they'd "met" before. They smiled, although by that time they'd passed.
If you wish to understand the local public transport, there is no substitute for consulting the official map.
Self-evident? Not to some.
In the German city of Dresden, there is a marvellously clean, efficient and regular system of trams gliding around a town where everything is new, a legacy of horrific and gratuitous bombing late in the last war.
Electronic signs at each stop display not just the next few trams coming, but in how many minutes they're due. You expect that on a railway station platform; not on a tram stop on the street. But this is Germany.
A family member, a student who'd been in Dresden a year, guided the traveller to her accommodation, hauling a wheeled suitcase almost a kilometre over cobbles, around corners, and along narrow streets and alleys, darting traffic, even one local walking a sheep on a leash.
Only to find, at the hotel, that there was a connecting tram stop on the next corner.
Students teach each other how to get from place to place on the tram. This student knew how to get there. But in a year in Dresden, she'd never looked at a map.
Do you think premium economy class is worth the extra price?