On my plane ride to Super Bowl 48 in New Jersey, I was startled awake by a Bronco party.

A jubilant woman was leading chants of “Broncos, Broncos, Broncos” and most passengers joined the chant, which was no surprise. We had, after all, departed from Denver.

Then a Seahawks fan stood up to loudly, and only half-seriously, demand the woman halt the chanting. This inspired her husband, Greg Thomas, to stand up and glare at the Seahawks protestor.

Thomas, a school principal and former college football star, stands a broad-shouldered 6-foot-6. The Seahawks protestor soon sat down. It was all in good fun.

When we landed at New York LaGuardia Airport, I talked for several minutes with Thomas about his son, Broncos tight end Julius. We agreed the football future of Julius was virtually unlimited. Julius had preferred basketball in college, playing for two NCAA Tournament teams at Portland State, before turning on a whim to football for his senior season.

Julius almost instantly became one of football’s best tight ends.

“The Lord gives us gifts, you know,” Greg said of his son.

I’ve been thinking about Greg and Julius this week as the Seahawks and Broncos prepare to tangle in Week 1 of the NFL season. So much seemed ahead on that night in New York when I talked to a proud father. Julius looked on his way to catching NFL passes for another seven or eight seasons, at least.

Julius retired Aug. 24, chased from the game by a foot injury. Always a superb student, he plans to pursue a PhD in psychology and study football’s toll on the brain.

The rapid exit offers a quick summary of the modern NFL. Change is the norm. Free agency, injury and an occasional trade transform teams almost beyond recognition.

The Seahawks, on a day that will live in Colorado infamy, devoured the Broncos, 43-8, on Feb. 2, 2014. (The Broncos had been two-point favorites.)

On Sunday, 1,679 days later, the Seahawks and Broncos tangle again at Mile High. These teams have only a vague resemblance to the mighty squads that met in New Jersey. (Thanks to Gazette colleague Doug Fitzgerald for uncovering the vast changes.)

Demaryius Thomas is the only Broncos starter still with the franchise. (Von Miller missed the game with a knee injury.)

The Seahawks are altered, too, though not as altered as the Broncos. Seven starters remain with the franchise, including safety Earl Thomas, who ended a contract standoff this week.

Teams didn’t always change so quickly. Randy Gradishar and Tom Jackson walked through life as two utterly different personalities who shared little other than the desire to pulverize ball carriers. They played linebacker side-by-side for a pulverizing Bronco decade, 1974-1983.

Karl Mecklenburg, a superb linebacker/end, and Dennis Smith, a vicious safety, led Denver’s defense together with brain-rattling hits from 1983-1994.

In yesteryear, NFL games resembled a long-running TV series. The same characters, season after season, playing the same roles in different dramatic situations. Continuity was common.

The Broncos and Seahawks are vastly different, but here’s the main thing that’s changed since Feb. 2, 2014:

The teams’ might.

The Seahawks featured one of NFL history’s most terrifying defenses, the “Legion of Boom.” The Broncos countered — pitifully, as it turned out — with a mighty offense.

During the 2013 season that ended in the Super Bowl disaster, the Broncos and Peyton Manning scored 606 points, best in the NFL. In 2017, the Broncos offense led (kind of) by Trevor Siemian scored 289 points, 27th in the NFL.

The Seahawks of 2013 allowed 217 points, fewest in the NFL. The 2017 Seahawks were merely mediocre, surrendering 332 points, 13th in the NFL.

Neither of the teams that met in Super Bowl 48 is considered a contender for this season’s Ultimate Game. The franchises are searching for new identities.

Maybe on Sunday, amid all the change, one of the teams will begin to find itself.