The NFC and AFC championship games.

The Saints versus the Rams.

The Patriots versus the Chiefs.

The old world versus the new.

If you take a step back a moment from New Orleans-Los Angeles and Kansas City-New England, you see two familiar threads emerging from the tapestry of matchups and hype — and, for that matter, Atlanta’s mayor bleating about how she’d like to see anyone but the Saints in the Super Bowl in her town.

(Don’t take offense, Saints fans. It was just a joke. Like the Falcons' 28-3 lead against the Patriots in Super Bowl 51.)

In both contests, you see the veteran guard being challenged by the sprightly upstarts. In the AFC it’s the redoubtable Patriots and their brain trust of Bill Belichick and quarterback Tom Brady — combined age: a creaky 107 — against fresh, young Patrick Mahomes and Andy Reid’s Chiefs (truth to tell, though, the 60-year-old Reid probably has arch supports older than Mahomes, 23).

In the NFC, it’s that familiar suit of Sean Payton (age 55) and quarterback Drew Brees (he turned 40 Tuesday) against the trendy tailoring of Rams coach Sean McVay (32) and quarterback Jared Goff (24).

Payton and Brees have been together 13 seasons now — an eternity in NFL terms by any measure, other than when they are measured against Belichick and Brady (an incredible 19 seasons). Payton and Brees are like old money, a mansion on St. Charles Avenue, or a piece of family jewelry handed down through the generations but probably held more dear. After all, great grand-ma-ma never set any NFL passing records.

McVay and Goff are fashion. They're like the latest West Coast hip-hop release, an oceanfront Malibu villa, or this week’s California food craze (poke nachos and a cup of matcha tea, anyone?). McVay is so California cool he has other teams trying to hire the next-best thing. The Arizona Cardinals inexplicably chose Kliff Kingsbury despite a 35-40 record at Texas Tech, apparently because like McVay he has a strong offensive rep and is movie star handsome. At least dead ringer Ryan Gosling could play Kingsbury in his biopic.

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The new generations eventually push aside the old. It is the natural order. And even though the 40-year-old Brees and his Saints and the 41-year-old Brady his Patriots are mighty tough to beat on their turf, they won’t be able to hold off Father Time forever. That guy is still undefeated, and much more menacing in his hooded cloak than Belichick in his pullover with the cutoff sleeves.

That doesn’t mean, of course, that the Saints and Patriots are going to lose Sunday. In fact, it would seem wise to bet the opposite. As the great playwright David Mamet acidly observed, “Old age and treachery will always beat youth and exuberance.”

It is true that past 40, the body often does not do what the mind commands — even bodies as well-preserved as Brees’ and Brady’s. It is noteworthy that Brees is 0-for-6 this season on throws that travel 35 or more yards in the air. That includes his underthrown game-opening interception last week against the Eagles, which helped put the Saints in an early 14-0 hole — a hole that took them virtually the entire game to climb out of before New Orleans scratched out a 20-14 victory.

But experience fills in the gaps glossed over by raw, aspiring talent. It tells you when to make the smart throwaway or when to hit the other team where they aren’t looking. Guys like Brees and Brady have pools of playoff-pressure-cooked resources on which to draw, the kinds of experience guys like Goff and Mahomes have only watched on film.

On Brees’ side will also be an amped-up Mercedes-Benz Superdome crowd that several times last Sunday unhinged the Eagles’ offensive plans (false starts, missed assignments and the like). The noise inside the venerable dome (the Rams are building a state-of-the-art $2.5 billion stadium in Hollywood Park, just to complete the Old vs. New theme) will likely have Goff’s brains leaking out his ears.

That said, it will not be easy for the Saints. The Rams are better now than they were when the Saints track-meeted them 45-35 in the Superdome on Nov. 4 — a win that gave the Saints that oh-so-important home-field advantage for this game.

The Rams have cornerback Aqib Talib (himself a ripe 32) this time around. Former Saints coach and Rams defensive coordinator Wade Phillips (age 71) will no doubt use him to hound Michael Thomas, who famously torched Marcus Peters last time.

And the Rams are arguably more of a ground threat than a passing threat with C.J. Anderson running wild in compliment to Todd Gurley. No way the Saints can allow 273 yards rushing, as the Dallas Cowboys did in the divisional round, and not expect to meet a similar fate (the Rams won 30-22).

It seems inevitable that one day will be The Day for McVay and Goff and Mahomes and the rest of their Romper, er, locker rooms.

But today, don’t bet against the Saints and Patriots coming to the end and giving them all a W.C. Fields-like brushoff with a modern twist:

Go away, kid, you bother me. Why don’t you go take an adulting class and try again next year?

Follow Scott Rabalais on Twitter, @RabalaisAdv.​