People often accuse me of being too negative. That’s one of the pitfalls of covering an NFL team that misses the playoffs 13 years in a row. But I am moved by the seemingly boundless optimism of many Bills fans.

A Las Vegas gambling site called Bovada recently posted the over/under for NFL teams in the 2013 season. They put the Bills’ over/under for victories at 6½. We ran a poll on our Press Coverage blog and 70 percent of respondents – die-hard Buffalo fans, I’ll wager – took the over.

The number seems high to me. I perused a schedule and tried to find games in which the Bills would be favored. I came up with three. In fact, another Vegas site posted probable lines for every NFL game and had the Bills favored in only three: Home vs. the Chiefs and Jets and on the road at Jacksonville.

So it depends on your perspective. I don’t mean to douse anyone’s enthusiasm. I’m encouraged by the signs of progress at One Bills Drive. It’s good to have Russ Brandon calling the shots instead of Ralph Wilson. Doug Whaley and Doug Marrone are a refreshing departure from Buddy Nix and Chan Gailey.

But new doesn’t necessarily mean better, not right away. Listening to Nix talk, you’d think he left behind the 1972 Steelers. There are still too many holes in this roster, too many young, unproven players for the Bills to make a serious run at .500 in Marrone’s first year as a head man.

Mike Pettine will be more aggressive, but an underachieving defense has lots to prove. And while there were good reasons to ditch Ryan Fitzpatrick, there’s no guarantee that his replacement will be good for 24 TD passes and 3,600 yards, especially if EJ Manuel is the starter from Day One.

The Bills are young, which is encouraging and sobering at the same time. You realize just how young when you’re reminded that Stevie Johnson is one of only six remaining players from the 2008 team: Rian Lindell, Kyle Williams, Fred Jackson, Bryan Scott, Leodis McKelvin and Johnson.

Johnson is an elder statesman and presumed mentor for a receiving corps that’s the youngest group on the team. The Bills are expecting big things from Robert Woods, the second-round pick; Marquise Goodwin, a third-rounder; and Da’Rick Rogers, an undrafted free agent with elite physical skills.

Rookie receivers tend to struggle with the adjustment to the NFL. Ask T.J. Graham, who suffered through a bumpy debut last season. It’ll be even tougher if Manuel, a rookie quarterback, is making the throws. Talent-wise, the kids represent a promising upgrade. But it’ll take time.

So the Bills are relying heavily on Johnson, both on and off the field. They need him to stay healthy, and they need him to produce as a No. 1 receiver while continuing to mature as a team leader. The idea of Johnson being a mentor for a stable of rookies is a tenuous one, to say the least.

Johnson is a good guy and an engaging presence in the locker room. Younger players gravitate toward him. But with that comes a responsibility to behave like a seasoned professional, to set a consistent and mature example for the impressionable younger players.

During his first three years as a starter, Stevie was unpredictable and often childish. At times last year, he seemed to be making a sincere attempt to grow up. He needs to do better. There are still times when he seems more interested in playing the clown and the entertainer.

If Johnson wants to play mentor to the young receivers, he can certainly tell them what not to do:

If you have to be on Twitter, don’t complain to God for letting you drop a pass that would have won the game. Don’t suggest that the North Koreans bomb Foxborough, Mass., because (ha ha) the Patriots play there. Be more like C.J. Spiller, who usually quotes Bible passages on his Twitter account.

Oh, and by all means, be careful about choreographing your touchdown dances. You might find yourself at your locker afterward, telling the media you cost your team a game. Avoid flashing messages on your undershirt after scoring TDs, too, because the coach might actually bench you.

Johnson could tell the rookies to avoid going on Jim Rome’s national radio show and admitting they don’t follow the Bills’ offseason workout regimen. He later complained that his words were “blown out of proportion,” and pointed out that he hasn’t missed a game in three seasons.

I’m sorry, but laugh about your workout habits, no matter how reliable you are in the games, and people are going to ask questions. People are funny that way. They had to wonder, especially when Johnson suffered a lower back injury that kept him off the practice field for the first voluntary offseason workouts.

Sure, he hasn’t missed a game in three years. But if I’m going to dog Mario Williams for injuries, it’s only fair to point out that Johnson has suffered his share, too. He played through a bad groin in 2011, which lingered into the 2012 season. Stevie was hampered by thigh and hamstring issues late last season, when he scored just three TDs in the last 13 weeks.

Johnson deserves credit for playing hurt, but might it have been different if he worked harder in the offseason? On Rome’s show, it was Stevie himself who said, “I’ve had three seasons with 1,000 yards, and that’s without doing, like, real football work. So you know, who knows what happens if I really put in work?”

Were we supposed to laugh off those comments as Johnson having fun with the media, as “Stevie being Stevie?” He sounded serious to me. He also made it sound as if gaining 1,000 yards makes everything else OK.

That’s the other thing that Johnson should tell the rookies in his new role as mentor. Don’t talk about your statistics. People don’t want to hear it. The only stat that matters is 16-32. That’s the Bills’ record in Johnson’s time as a starter, the record that got Gailey fired and Fitz run out of town.

That’s why everything is so new around here, and why so many rookies will be in vital positions next season. It’s a new, exciting era. The Bills are young and people should be patient. The transition will be bumpy. People have a lot of growing up to do.

Management can only hope that, for the new guys, the process moves along a little faster than some.