Les flâneurs sans flan

I just took advantage of the BNF's website letting me know I wouldn't get a spot Tuesday morning to do a little grocery shopping in the Parisian manner, at least in the American fantasy thereof. What this meant was that I leisurely strolled to a market street in the same district but (I now know) not remotely nearby, stopping along the way for a pain au chocolat and the other striped shirt (the one with the red stripes) I'd been coveting. And I now have the makings of a heck of a salad. All that was missing was a straw basket.

Yes, life is tough. I do, however, have one Parisian food-related grievance. When one thinks of Paris, one thinks ("one" = this blogger) of sitting in a café in the morning with a pastry and a coffee. And indeed, coffee and pastries are everywhere, and the latter are virtually always amazing. The issue is that it's very unusual to be able to purchase and consume both in the same establishment. (It's also very unusual to see people go the WWPD route, eating pastries on the street, on their way to or from a coffee at the bar.) What's going on? Is the coffee-and-pastry pairing a specifically American phenomenon?

I think I've narrowed it down to the following possibilities:

-The pastries are just for tourists. Actual French people either just have the coffee out or eat breakfast at home. Evidence supporting this is that while I'm living in a neighborhood that's not remotely touristy, the only places I've heard English around here have been bakeries.

-Locals run out to buy the daily croissants, then return home for their coffee, then leave for the workday. This could be, but given that buildings here tend to be walk-ups, it sounds exhausting. It could, however, explain the French Paradox.

-Pastries are served in cafés, but only during early-morning hours my jet-lag has yet to permit me to experience so far. This is the best reason I've come up with to kick the jet-lag prior to my first 9am BNF reservation.

-There is, during at least some parts of the day, an implicit BYOCroissant policy in cafés. I doubt this one's it, but it's far more likely than a BYOCoffee in the bakeries, considering that coffee's never to-go and bakeries either don't have seats or, on the rare occasions they do, also serve coffee themselves.