GREEN BAY — Brett Favre knows how it looks.

The now-retired Green Bay Packers quarterback, whose unexpected decision to exit the stage after 17 NFL seasons sent Wisconsin into a state of shock Tuesday, knows fans will never understand how he can walk away from the game after one of his best seasons, how a guy who'll do anything to win can leave behind a team that fell one under-thrown pass short of the Super Bowl.

"I had so many people saying, 'You look like you had a lot of fun out there this year,' '' Favre said, "and I did."

Just not as much fun as he used to have.

In an emotional farewell news conference Thursday, the 38-year-old face of the franchise made it abundantly clear he retired because the strain of carrying a team, a city and a state on his back finally caught up with him.

"I expect a lot out of myself and certain things are expected of me within this organization and I tried to live up to those all the time," Favre said. "And Brett Favre got hard to live up to."

That's what happens when you set the bar at a Hall of Fame level, show up for work every day for 16 seasons and play every down like it's your last. You have to pedal harder and harder just to keep up, and eventually you wear out.

Until Thursday, Favre's reasons for retiring had been doled out only in voice-mail snippets. That caused wild speculation about Favre's state of mind, with general manager Ted Thompson and coach Mike McCarthy catching heat for supposedly not showing Favre enough love or giving him enough help (read: Randy Moss) to ensure his return.

Favre repeated an earlier statement that he retired because he was mentally tired, only this time he said it in such a way that it erased all doubts. He promised his wife, Deanna, that he wouldn't get emotional Thursday, but he was fighting back tears — unsuccessfully — 25 seconds into his opening statement.

Unless Favre has dramatically improved his acting skills since his cameo in "There's Something About Mary," his reaction was sincere. He looked and sounded tired, and when he said he wouldn't be changing his mind on retirement, few in the large media gathering doubted him.

The pressure of preparing for games and having to outdo himself Sunday after Sunday finally led to burnout and there was nothing Favre or anyone else could do about it. With a performance so convincing it put all speculation to rest, Favre absolved Thompson and McCarthy of any blame.

"None of those things have anything to do with me retiring, and that's from the heart," he said. "I've given everything I possibly can give to this organization, to the game of football, and I don't think I've got anything left to give. I know I can play, but I don't think I want to. ... There's only one way for me to play the game and that's 100 percent.

"I will wonder if I made the wrong decision. I'm sure on Sundays I will say, 'I could be doing that, I should be doing that.' But I'm not going to sit here like other players have said in the past (and say) I won't miss it, because I will. But I just don't think I can give anything else, aside from the 3 hours on Sundays, and in football you can't do that. It's a total commitment, and up to this point, I have been totally committed."

Favre wondered after the 2005 and '06 seasons if he could still play at a high level. He answered that question emphatically as the Packers went 13-3 last season, but the cost was high.

Deanna noticed that Favre was more stressed out than he'd ever been in his career, that the commitment to maintain the level of play he and everyone else expected of him was exacting a terrible toll.

"There were numerous Saturdays (before) home games where I was here at 8:30 at night watching film," Favre said. "I had never done that before. It was never enough for me. Deanna knows this: After numerous games I would come home and after a couple of hours I had the computer out and I was watching film of the upcoming opponent instead of enjoying the win we just had. At some point, you've got to relax and enjoy and I found myself not enjoying it as much."

Brett Favre? Not enjoying football? Is there any doubt now why he retired?