CHARLOTTE, N.C. -- Cam Newton remembers all of the criticisms.
He couldn't read defenses. He threw off his back foot. He wasn't accurate enough.
The Carolina Panthers second-year quarterback laughs them off these days with a knowing, confident smile.
"If I base my career off things people have said that I couldn't do I would have quit this game a long time ago," Newton told the Associated Press on Wednesday. "You can't listen to what the naysayers say about you because their opinion is just that -- their opinion."
Newton wowed the naysayers in his first NFL season with a record-setting performance, eclipsing Peyton Manning's record for yards passing by a rookie and rushing touchdowns in a season by a quarterback. He captured AP Offensive Rookie of the Year honors and developed into one of the league's more popular players virtually overnight.
Now everyone wants to see what he does for an encore.
The Panthers went from last in the league in total offense prior to Newton's arrival to seventh overall last season. They finished 6-10 -- a four-game improvement over the year before -- but expectations are even higher this year given Newton has an offseason to work on his skills and gain a better working knowledge of coordinator Rob Chudzinski's ever-changing scheme.
"There were a lot of times last year I felt like I was guessing," Newton said. "That can happen in this league and sometimes it showed."
Coach Ron Rivera said there's nobody who has worked harder the past two seasons than Newton -- and for that he has been rewarded.
When he's asked about proving himself, he just smiles knowingly.
"The thing is, I don't play this game to prove nothing to nobody but myself," Newton said. "I've said it once and I'll say it again, there are a lot of expectations out there for Cameron Newton but none of them are going to ever exceed what I want for myself. And that's how it is going to be until I'm no longer able to play this game."
Copyright 2012 by The Associated Press