"I'm not angry, I'm from Philly" became Monteiro's default explanation for all behavior that seems oddly foreign in the Golden State.
In California, Monteiro observes, motorists say, "Hey, I was kind of thinking, maybe, ahh, you might have taken - [long exhale] - my parking space."
In Philadelphia, he notes, "our communication style is very different. You tend to be very clear about what you need from people at any particular time."
Clear. That's a West Coast euphemism for rude.
Take the same disputed parking space and a Philadelphian. The response, Monteiro says, is "You. Move. Now."
Short, and nothing sweet about it.
"There have been several times in the last few years, including client meetings, where I'll say something in what I perceive to be a totally normal voice, and the room goes dead," says Monteiro, a founder of Mule Design Studio, a Web strategy, branding, and identity firm. "At which point, one of my friends will say, 'He's from Philly,' and everyone goes, 'Ohhhhh,' like it all somehow makes sense."
Like it's a liability.
Please note, Monteiro has lived in California since 1999. But Philadelphia habits, bred deep, are hard to shake.
The truth is that we're so used to anger, aggression, and all-round pernicious behavior that would be inexcusable almost anywhere else (though not, perhaps, New York, Chicago, and Boston), that we're inured to the effects.
It's like Stockholm syndrome. Except we're our own captors.
Living here can be like living in a perpetual state of road rage and airport travel, even when we're off the Schuylkill or away from the shame spiral of Philadelphia International.
Every time Philadelphians leave, escaping the 700 Level mind-set, they notice how sweet, how pleasant, how - I know this may come as a shock - helpful people, even strangers, can be.
Some theorists blame our behavior on a massive chip we carry on our shoulders that we're not New York - where people are certainly rude, though not necessarily angry.
But many Philadelphians are too provincial to care about besting New York. They gave up, long ago, on a quest for greatness or emotional equilibrium.
Our behavior is, in part, rooted in loss, the bathos mind-set symbolized by those public television specials Things That Aren't There Anymore. The city was once so great, so big, symbolized by our massive City Hall, and now some neighborhoods and lesser suburban towns remain in a deciduous state.
In recent years, notable additions - a marked vitality in the city's burgeoning core, and a winning baseball team - have sparked the region. Philadelphia remains eminently livable, much more so than New York or D.C., the latter becoming impossibly expensive and marked by political rancor.
But what remains in Philadelphia is the intractable attitude of righteous indignation toward anyone who challenges an opinion, coupled with an unrelenting suspicion of outsiders, even those who move here happily.
The egregiously slow march of political reform in the city or Harrisburg contributes. The given assumptions are that we're stuck with pay-to-play and what's-in-it-for-me, and that much of public service is a business rooted in money, perks, turf wars, and resistance to change.
Monteiro is on to something, boiling our essence down to a slogan, a T-shirt. (Find them, for men and women, at http://feedstore.muledesign.com)
Remember the "so-called" Twinkie defense? That arose when San Francisco Supervisor Dan White murdered Mayor George Moscone and Supervisor Harvey Milk, and psychiatrists and lawyers working on his case argued - successfully, I might add - that White's judgment, already impaired by depression, had been further hampered by sugary junk food.
Instead of the Twinkie defense, we have the Philadelphia defense: It's not inappropriate behavior, we say, it's just this place.
Mule Design's "I'm not angry, I'm from Philly" T-shirt is the first acquisition in my fall wardrobe, available in acrimonious brown and irate orange.
Already, colleagues are hankering for their own.
But back off, jerks, the top's mine.
Contact columnist Karen Heller at 215-854-2586 or firstname.lastname@example.org.