ROME -- On the day before the Rome Derby, in which AS Roma beat Lazio 3-1 on a viciously hot afternoon, I met Luciano Rossi and his son at a restaurant near the Roma training facility. A lot of people from the club come here for lunch, including Francesco Totti, now retired but still the most beloved living Roman. Both Rossi men are Roma official team photographers, and their roots in this city stretch back at least seven generations. Luciano's family comes from Trastevere, the old neighborhood south of the Vatican, and he feels, in his heart, more connected to his city than his country.

Luciano often gets asked whether he's Italian when traveling overseas with the team and someone hears his accent.

"No," he will reply. "We are from Rome!"

That's what was on display Saturday, and why Italian football so easily finds its way into your blood. Italy is a very young country and a relatively new idea. Its cities, however, are very old, many of them former city-states with their own history and mythology -- their own food and wars won and lost and a unique way of defining what it means to be a citizen. When their football teams play, ancient things get ripped out of the past and put on public display.

In Rome, that's only heightened.

This sounds silly, but it's always startling to be driving around the city to meet someone for something as modern as a meeting or a cocktail and just pass the spot where Julius Caesar was stabbed, or make a right at the Coliseum.

No big deal.

It's just the f---ing Coliseum!

Rome conquered the world, rose and fell, and nearly everything that has happened in the city since flows from that identity.

Especially the football culture.

Lazio fans gesture to the opposition in a rivalry where the emotions, and the complicated feelings both Lazio and Roma supporters have about being Italian and Roman, don't stop and start with a whistle. Filippo Monteforte/AFP/Getty Images

Inside the city, most people are traditionally fans of Roma, and in the suburbs and outskirts, more people support Lazio. Family plays a role, maybe more now than geography. Like everything in Italian life, politics play an important role. Roma's ultras are left-wingers, and Lazio's ultras have deep roots in Italy's fascist history.

A year ago, to mock a pregame celebration honoring Anne Frank, Lazio fans printed signs that showed Frank wearing a Roma jersey. During the celebration itself, some Lazio supporters sang an old fascist song named "I don't care!" During games, the Lazio stands often give the Roman salute in unison, which most people know from its most recent proponents, the Nazis. The Rome Derby can no longer be played at night, as police try to wrestle with the postmatch violence.

An Italian rivalry is unlike nearly any other, and a Roman rivalry involves so many grievances and loyalties and passion, some very fresh and others stretching back two thousand years, that it's nearly impossible for an outsider to understand, much less explain. But anyone who comes here for this match can feel those energies.

They crackle in the air.

Being in this city for the past three days as this match approached was truly one of life's great experiences. This is something you must come see for yourself, at least once. It's palpably bigger than 90 minutes of a sporting event. Walk the narrow streets of Trastevere and find little cafes and restaurants tucked in against ivy-covered walls, with plates of the famous Roman pastas like Cacio e Pepe and carbonara served beneath strings of tiny white lights. Order tripe or artichoke. Walk with a perfectly dressed old man through the streets and ask him to talk about his grandfather and the unchanging city that connects them. Roma and Lazio both exist as load-bearing pieces of civic life and in how the past is transmitted from generation to generation.

Yesterday after lunch, I went over to the AS Roma training facility where one of the top executives, Mauro Baldissoni, talked about the predictive modeling algorithms the team is creating and then almost immediately got nostalgic about how much AS Roma meant to his grandmother, who didn't care for, or even really understand, the sport.

"Roma is part of your life," he said. "For her, Roma was family."

On the day of a game, the big family lunch got moved up so her husband and sons could go to the stadium. While she cleaned up, she turned on the game in the other room, because even though she didn't know the rules, she heard that roaring crowd and felt connected to her men.

"She knew her family was there," Baldissoni said.

To him, the historic innovation of ancient Rome and the beautiful life made famous (and also dissected) by Fellini belong together, as Roman as pepper and cheese.

"They invented roads," he said. "They invented the aqueduct."

Then he laughed big, letting out a little of his wicked sense of humor.

"... but also taxes," he said with a grin.

Derby day: Roma defeated Lazio 3-1, a victory the club sorely needed. Filippo Monteforte/AFP/Getty Images

On Saturday, the Stadio Olimpico rocked and echoed with that low-pitch moan familiar to football fans, where singing and chanting make the air hum with a constant noise. It rises in peaks, falls in valleys, but it never stops. The sound remains in your ears long after the game ends. Nothing else really sounds quite like it.

During a Roma anthem, when fans held flags still in the air out of respect, the Lazio supporters whistled through the entire song. Chants went back and forth, insults lobbed from south to north and back again. Roma fans unfurled a banner that makes fun of Lazio for not really being Roman, for being some modern creation.

It's almost crazy the authorities let this happen.

The first Roma goal was scored by Lorenzo Pellegrini, one of only three Romans on the roster, who grew up in the same neighborhood that birthed one of the ultra groups in the Curva Sud. Lazio equalized, but Roma scored two more to clinch the victory, which the club badly needed.

Both groups of fans chanted and sang even after the contest had ended, because in the most important way, it hadn't ended at all. The emotions behind the rivalry, and the complicated feelings both Lazio and Roma fans have about being Italian and Roman, don't stop and start with a whistle. The derby doesn't end but merely pauses, because like the city that birthed both clubs, it is eternal.