Global Motorsport Media
F1 chief executive Bernie Ecclestone told Austria's Salzburger Nachrichten newspaper that the fact Jenson Button beat the 2008 world champion was the "biggest surprise" of last year's world championship.
Fellow Briton Paffett admits 2011 "was a hard year in lots of respects" for Hamilton.
"Lewis wasn't himself on track or off track," the 30-year-old told the Sun. "He had various problems with his personal life or whatever.
"Hopefully he has had a chill-out over the winter. We're all hoping he has gone away and sorted himself out a bit and will come back to his best -- because at his best Lewis is as good as or better than anyone.
"And he can definitely fight for the championship," added Paffett.
"He wants to be back winning races. We didn't see the Lewis we all love last year and we need him back. I think F1 needs that, too."
McLaren, meanwhile, declined to comment on reports Hamilton has been summoned to appear in Munich at next week's assault trial of his friend Adrian Sutil.
According to Auto Motor und Sport, McLaren did not want to comment until Hamilton actually receives in the mail the court's formal summons.