Why does Jimmy Rollins keep doing this?

Jimmy Rollins has got to stop making predictions. Not only are they always wrong, they are outright stupid. He told the media the Phillies would win 112 games this year. They won 93 games. Before the start of the World Series he told Jay Leno the Phillies would beat the Yankees in five games. As you have probably heard by now, Yanks prevailed 4-2. Why aren't there teammates telling him to shut his trap? He's not only making himself look incompetent, it puts unnecessary pressure on the rest of the team. What was the dumbest occurrence of a player making a prediction?