Every fan of every team does it to some degree after Week 1. Overreact, that is. Either their favorite team won big in their first game and is now a sure bet to reach the Super Bowl, or they lost and are the worst team in the NFL.

It’s fun to overreact and, better yet, it’s part of being a fan. When your favorite team is projected to go 2-14 and finish dead last in their respective division, it’s fun to play the “that idiot at the Scores Report has no idea what he’s talking about” card after winning Week 1. And when your team is on the losing end of a big upset, it’s almost therapeutic to go overboard in shredding them to pieces.

Below are 15 overreactions from the first week in the NFL. Some of these overreactions might prove to be true by the end of the season, while some might not even hold water after Week 2. They’re also premature, over the top, and in some cases ridiculous. But I guarantee that some football fans are thinking these exact thoughts a day after their team’s first game.

1. Without Tom Brady, the New England Patriots won’t even make the playoffs. Teams will use Matt Cassel’s inexperience against him and the Pats will unravel with a below average secondary.

2. Now that Tom Brady is likely done for the season, the Jets will win the AFC East. Brett Favre has made New York a legitimate playoff contender and Thomas Jones will have a bounce back season running behind an improved offensive line. And one of the big things that has hampered the team in the past, the run defense, has obviously been fixed after shutting down Ricky Williams and Ronnie Brown on Sunday.

3. Last year was just a hiccup – the Saints are Super Bowl contenders again. Drew Brees torched a good Tampa defense on Sunday for 343 yards and Reggie Bush is almost unstoppable coming out of the backfield in the passing game. What defense is going to stop New Orleans’ offense?

4. The key to Jacksonville’s success on offense is balance and without the threat of a running game, David Garrard falters. More teams will stack the box like Tennessee did Sunday in efforts to take away the run. Once that happens, the Jags will be exposed offensively and will continue to struggle against better defensive teams. They’re still obviously a playoff contender, but people need to relax on all the Super Bowl talk.

5. The 2007 Cleveland Browns were a fluke. The defensive upgrades the Browns made this offseason won’t have much of an impact and coordinators will figure out ways to hold Cleveland’s offense in check like Dallas did Sunday.

6. Donovan McNabb is a MVP candidate again. Forget the Eagles’ limitations at wide receiver – McNabb will overcome that with help from dynamic runner Brian Westbrook. Just keep him upright and McNabb will lead Philly back to the playoffs.

7. The balance of power in the NFC West has shifted from the Seahawks to the Cardinals. Without a running game, Seattle’s offense is unbalanced and the Bills proved Sunday that the Hawks’ defense is overrated. Kurt Warner still has game, Edgerrin James is running like he did three years ago and the Arizona defense is finally starting to come together.

8. The Colts have to be concerned with Peyton Manning’s health. Physically he might be okay, but his timing is off and it doesn’t help that Jeff Saturday will continue to miss games with a knee injury. And after Matt Forte gashed them for 123 yards on Sunday night, the run defense is once again a major concern as well.

9. The Giants are going to be just fine. Brandon Jacobs is running like a freight train, Eli Manning looked great in the first half Thursday night and the defense looked just fine without Michael Strahan and Osi Umenyiora.

10. The Bengals are toast. The defense has improved, but Rudi Johnson was the backbone of the offense three years ago when they made the playoffs and now that he’s gone, the rest of the unit will struggle. It also doesn’t help that this is the most dysfunctional team in the NFL.

11. Matt Ryan will run away with the NFL Offensive Rookie of the Year Award and defy history by succeeding as a first year starting quarterback. He has already won his teammates over with his leadership and he’s well above the NFL learning curve as a first year player. Teamed with Michael Turner, Roddy White and a young, improving defense, the Falcons will be one of the surprises in the NFC.

12. The Detroit Lions have the worst defense in the NFL. Their front seven can’t stop the run, the secondary is overmatched and outside of DE Dewayne White and LB Ernie Sims, the entire unit is void of talent. The offense can be explosive, but it won’t matter if the defense yields 30 points a game.

13. Forget all the concerns about the Steelers’ offensive line. It’s fine and once again Pittsburgh is the team to beat in the AFC North.

14. Despite high expectations coming into the year, the Texans are still a year away from competing for the playoffs. The offensive line still needs work, the team is lacking a true threat at running back and the young defense needs time to develop.

15. Now that the Bears have a running back and a quarterback that doesn’t make mistakes, they’ll lean on their defense and special teams like they did in their Super Bowl season two years ago. The thrashing of the Colts Sunday night was just a beginning of things to come for Chicago this season.

As previously noted, some of these observations might pan out by seasons end. It’s only a matter of time before we find out.