Brett Favre “100% positive” he won’t play again

According to si.com Minnesota Vikings QB Brett Favre told an unnamed player that he is “100% positive” he will not play again. What does this mean? If this is really true the Vikings are in big trouble at the QB position this year. If this is just another one of Favre’s games hopefully the Vikings still make a decision on a QB of the future. I would be absolutely shocked if Favre really thought he was never going to play again, but then again, does anyone really know what Favre is thinking?