The past is the past, and each team is different, and I get that. Matthew Stafford isn't the same guy who was benched the last time the Cardinals visited Detroit in 2015, and that's not just because he got a new mega-contract. The Cardinals aren't the same team that floundered disappointingly in 2016.

But the past still can be fun to revisit. The last time the Cards opened up in Detroit was a memorable one for me. That was the day Anquan Boldin burst on the scene with his 10 catches for 217 yards and two touchdowns, back in 2003. How about you, Tyrann Mathieu? Do you have a memorable opening game at any point in your life?

"I always think about my rookie season and nobody thought I was going to be able to play, and I go ahead and make that big-time play against St. Louis," Mathieu said. "That was one of those special moments for me."

See, that moment, to me, does have some bearing. That Mathieu that burst on the scene in 2013? That Mathieu who dominated in 2015? That's the guy we've been seeing in camp and the preseason. He's a big reason why there is optimism about this defense. Sometimes, you look backward to see what is coming. With the Badger, that seems fitting as the Cardinals finally get started in the regular season.

-- To me, the keys Sunday are fairly simple. Offensively, can you allow Carson Palmer to have time to throw the ball down the field once in a while, protecting against an at-best average pass rush? I know John Brown keeps saying he's not totally healthy, but I think Smoke is healthy enough to make at least some sort of impact.

-- Defensively, it's that defensive line. If I had to guess, I'd guess Robert Nkemdiche wouldn't play, but we are still two days away. In the end, with seven defensive linemen, at least one is probably inactive every week anyway, and I just don't think they'll risk Nkemdiche coming back too fast when there is confidence in the other guys. That said, they have to hold up. This defense has the pass rushers. They definitely have the playmakers in the secondary. But to get there, you have to lock down the run, something this defense has done well the last couple of years.

-- Offensive coordinator Harold Goodwin, on newcomer Alex Boone — who was a right guard those years in San Francisco when playing with old/new teammate Mike Iupati, and then went to the left side after Iupati came to Arizona: "We all know that's Mike's position," Goodwin said with a chuckle. "Kind of funny, I was talking to Mike, he said, 'Alex called and he wants to come here but he's not playing left.' "

Reminded me of Evan Boehm insisting he wasn’t going to be displaced on the right side either.

-- Goodwin said Boone fits the Cardinals' style, but "you know I don't like anybody," he added. "That's just my nature. I won't like anybody until I'm standing on the podium holding a Super Bowl trophy. Then I'll start liking guys."

-- The Lions have a pair of former Cardinals tight ends. Darren Fells is there as a starter, a guy who will try and get going again after having a disappointing 2016 in Arizona, which is one reason the team let him leave in free agency. The Lions also signed Hakeem Valles to the practice squad this week. Any little edge, right?

-- Speaking of tight ends, Goodwin chuckled again when asked if the tight ends would be more involved in the passing game. (In my opinion, I wouldn't hold your breath.) Goodwin knows Jermaine Gresham got a big contract, and Troy Niklas has looked solid and stayed healthy. But as he as mentioned before, from a long ago warning from Arians in a meeting, "We pay Larry (Fitzgerald) a whole lot of money."

-- Stafford's numbers since being benched in Week 5 against the Cardinals in 2015: 50 touchdown passes, only 15 interceptions, 67 percent completions and a 99.1 quarterback rating. Also, in what is coincidence, but take it for what it is worth, that 2015 Detroit game was a late kickoff — 4 p.m. locally, 1 p.m. in Arizona. It wasn't early, like Sunday's will be.

-- Defensive coordinator James Bettcher, like the other coaches, is convinced Justin Bethel has earned that starting job. The reason, among others, is that health allowed him to practice.

"When you are finally healthy, and you get a whole offseason to work your craft, it does wonders how you progress as a player," Bettcher said.

-- Fitzgerald needs 82 yards receiving to become only the fifth player to have 1,000 receiving yards and eight touchdowns over a career in season openers. The fabulous four so far? Don Maynard, Andre Reed, Randy Moss and Jerry Rice.

-- Finally, back to Mathieu. One of the things the Cardinals lost last year when the Honey Badger was not Badgeriffic went beyond dynamic play in the secondary. It lost an emotional jet engine, which Mathieu simply couldn't be when he isn't playing like he knows he can. That component is back.

"I try to feel out games," Mathieu said. "Some games I won't say a word. Other games I'm pretty well vocal. I won't know until I actually get to game day."

It's meaningful. Said Patrick Peterson, "He finds ways to pass his energy to his teammates."

See you Sunday. The regular season is here.