We watched the girl with the ice cream as she walked away. She was pretty. Or so we think. We don't remember. Our eyes were on the ice cream.

We had just eaten lunch, which presented­ a dilemma: We were full, but there went by that heavenly ice cream.

"How 'bout we get one cone and share," Jessica said.

Jessica is nothing if not a problem solver.

Through pantomime, she motioned to the counter guy that she wanted precisely what the young woman had ordered. Confusion followed. As Jessica pointed down the street, the counter guy wore the befuddled expression of someone wondering why a customer would want a parked car or a tree. Jessica mimed more emphatically, like someone who speaks louder to a person who doesn't speak the same language. The guy's face lit up with the universal "ah-ha, I get it!" and he put together the complicated cone.

It involved coffee ice cream with dulce de leche (exquisite milk caramel) mixed with hazelnuts and dipped in chocolate that formed a hard shell around the ice cream. Oh, did I say hazelnuts?

I'm sorry. That's the part that is in dispute, isn't it?

Unaware at the time just how consequential that ice cream cone would become, I did not take notes. I just stood on the corner trying to lick more than my share.

On our last day in Buenos Aires, we sat on a bench enjoying one final cone each and did what the city's residents do: argued about which of the heladerías (ice cream parlors) makes the best ice cream. Porteños, as residents of Buenos Aires call themselves, debate ice cream like barbecue hounds debate barbecue.