The feral children of Neuilly-sur-Seine
Neuilly-sur-Seine is overrun with children on scooters. Not mopeds, but the little two-wheels-and-a-handle-on-a-tall-stick things that disruptive tech bros went all-in on last year. You can also find those specific tech-bro scooters, lying in the gutter, floating in the Seine, or hanging from power lines, like their riders want to vicariously have a debauched Parisian experience through their vehicles. But these are not the kids' scooters. The kids' scooters are just plain black (or green or pink or yellow or...) scooters that you can buy at a department store. And they're everywhere.
The closest experience I have had to this was that brief period in the US between the introduction of Heelys and the manufacturers' legal counsel breaking out of whatever closet they had locked him in so they could release them: kids are moving even faster than kids normally like to move, in every direction at once, and in ways that that both seem extremely dangerous and make me feel uncomfortably old.
The kids take to it naturally, though, and seem to love buzzing my dog when we go on walks. The conversation takes on a drive-by quality: "bonjour, le chien blanc!" whoosh "au revoir, le chien blanc". It helps to imagine it with the Doppler effect in both directions.