Working on the NFL Network is tough. Not because of the demands of the job or because it’s difficult being on camera. That’s easy. I got that down.

It’s because of the rings. There are so many rings. They’re everywhere. Michael Irvin, Deion Sanders, Kurt Warner, Marshall Faulk, Warren Sapp, Willie McGinest — all those guys have Super Bowl rings. And they make sure you know it. They wear them on set. It’s a constant reminder. I know they’re walking around Arizona at Super Bowl week right now, flashing those rings.

I played in the NFL for eight years, but if I had to sum up my career in one word, it’d be “incomplete.” We all play the game for one reason. Yeah, we play for the love of the game, the personal accolades and all that other stuff, but what we all really play for is the chance to call ourselves a champion. Until you slip that Super Bowl ring on your finger, you’re never considered the best.

That’s the only thing those guys have that I don’t. And no matter how far removed from the game I get, it still haunts me.

Imagine getting close to the top of the tallest mountain — so close you can see it, even feel it — and just as you reach for the top, you start sliding back down the mountain, watching the peak disappear into the distance. I’ve had that feeling a few times.

Maybe the worst was in the 2006 playoffs. (Chargers fans, now’s the time to look away.)

We were 14-2 that year and, as the No. 1 seed going into the playoffs, we hosted the Patriots in the Divisional Round. We had a squad that year in San Diego. I was one of 11 Pro Bowlers on that team, the most of any team in the league. Philip Rivers, LaDainian Tomlinson, Antonio Gates, Marcus McNeill, Nick Hardwick, Kassim Osgood — we were stacked. It was the best team I’ve ever been on.

Late in the fourth quarter, we were in control of the game. We led by eight with 6:25 left, but the Patriots were mounting a drive. It was 4th-and-5 and they were just out of field goal range, so Bill Belichick went for it (like Belichick does). Tom Brady threw a short pass over the middle intended for Troy Brown, and our safety Marlon McCree picked it off.

I thought that was it. I thought we had the game wrapped up.

But Marlon had other ideas. Instead of taking a knee, he tried to spring a return. Troy Brown came up behind him and poked the ball out. Fumble. The Patriots recovered. It was a nightmare. The Patriots got a fresh set of downs and they gained nine yards on the play. Five plays later, they were in the end zone. They twisted the knife even more by tacking on the two-point conversion.

Moments earlier, the game was in our hands. We would have had the ball with an eight-point lead and time winding down. Instead, it was a tie game.

It still plays back in my mind so vividly. I can see and feel myself running down the field waving my arms at Marlon yelling, “Go down, go down!” I was sick to my stomach.

We couldn’t get anything going on the next possession and were forced to punt. Then, Tom Brady did his Tom Brady thing: he drove them down the field for a go-ahead field goal with just over a minute left. We missed a last-second field goal that would have sent the game into overtime.

That was that. The Pats were moving on to the AFC Championship Game. We were going home.

We had another great year in 2007, when we went 11-5 and beat the Titans and the Colts on our way to the AFC Championship — one game away from the Super Bowl, two wins away from that ring. But we ran into those Patriots again. And this time, they were a perfect 17-0 and seemed to have a date with destiny. We were in it late, but eventually we lost, 21-12.

That was my third year in the NFL, and I’d never get that close to a Super Bowl again.

I said that 2006 team was the best I’ve ever been on, and it was. The 2006 Chargers were probably one of the best teams to never win a Super Bowl. When you’re young, you don’t really understand how special a group like that is. Teams like that don’t come around often, and when they do, they rarely stay around. When you’re young, you think your team will have a chance to compete for a championship every year, but that’s far from the truth.

It creeps up on you. One guy gets released, another leaves as a free agent. A position coach or coordinator gets poached by another team. You only have a small window with that special group of guys — that amount of talent, that coaching staff — before the business of football tears it apart. Before you know it, you’re a whole different team. That’s when you realize how small that championship window can be.

In 2010, I was one of those business casualties of the NFL. After injuries limited my play for three straight seasons, the Chargers released me.

I was still thinking about that elusive Super Bowl ring. I was so close to getting that chance, and now, adding the insult of being waived to nagging injury, I was doubting I’d ever get that chance again. Physically, I wasn’t the same anymore. I could still play, but I wasn’t the same Shawne Merriman. I didn’t have the same explosiveness. So I was looking for a team that needed an experienced veteran to provide leadership as they chased a championship.

Five teams claimed me off waivers. The Bills were one of them, but I didn’t want to go. They were 0-7 at the time. At the end of your career, especially after you’ve been close, chasing that ring is all that matters. It’s the only thing that drives you. How was I going to compete for a championship in Buffalo?

I told Buddy Nix, the Bills GM at the time, that I wasn’t going to Buffalo. I said, “You’re not going to the playoffs. Let me go play for a team that’s gonna contend.”

His response? He reminded me what the fines would be if I didn’t show up. It was something crazy like $10,000 for every day I didn’t show.

So I said, “What time’s the plane?”

As you know, I never got that ring in Buffalo. We never even went to the playoffs. I signed an extension because I felt like the management was making good moves to build a winner, but the winning never materialized.

Missing that Super Bowl ring is one of the most hollow feelings you can have. When I look back at my career, it’s a pretty good resume: I was a first-round draft pick, Defensive Rookie of the Year, a three-time Pro Bowler and three-time All-Pro. I led the NFL in sacks in 2006 with 17. But that stuff only matters early on in your career when you’re still young and it’s all about you and you’re chasing that next big contract. Later on in your career, when the end is in sight, getting that ring is all that matters.

That’s one of the big reasons I retired when I did in 2013. The opportunity to win a ring wasn’t there. Sure, teams were interested, but I wasn’t getting the offers from teams that had a real shot at winning. If a contender wanted me, I would have played, no doubt. Maybe if injuries hadn’t taken their toll, things would be different. Maybe if Marlon McCree just got down. Maybe if that Tom Brady guy never came around…

This weekend, Russell Wilson goes for his second straight Super Bowl ring while Tom Brady chases his fourth. Think about that: Russell has been in the league for what, five minutes? And look what he’s already done. It’s incredible. Meanwhile, Brady’s chasing immortality. Four rings in six tries would put him on another level.

If I got a call from Belichick or Pete Carroll today asking if I wanted to be the 53rd man on a roster for Super Bowl XLIX, I’d do it in a heartbeat. Anything to have another shot at that ring. That’s how important it is. It’s something that stays with you even after you’re long gone from this earth. Once you win that ring, you’ll always be a Super Bowl champion. And that’s something that’s going to continue to haunt me (and probably most of my former teammates as well) forever.

I never won a state title in high school. We never even got there. I never played in the ACC Championship at Maryland, and that AFC title loss to the Patriots was the closest I got to the Super Bowl. I went my entire football life without even playing in a championship game. That hurts.

This game is about windows, and some are bigger than others. The Patriots’ window has been open 14 years and counting. The Seahawks have made the most of their Super Bowl window the last two years, but how long will it last? Will it slam shut like mine did, or will Pete Carroll and Russell be the next Belichick/Brady combo?

My window has closed and been locked up tight. Inside, there’s a room full of men who’ve played in the biggest game on the biggest stage in the world and come out on top. It’s an exclusive club of players from 48 teams that have reached the pinnacle of this sport. And they all have the rings to prove it.

And I’m on the outside looking in.