Just curious where you heard that.
I may have interpreted him wrong. But...
1) Last year when he was hurt he talked about how boring it was. I know he could have simply meant that he didn't like sitting on the bench when he could be out there but it didn't seem like he meant it in that context.
2) Yesterday at the Nats game he was doing a Q&A thing on the scoreboard and he said he enjoys watching all these other sports more than baseball.
Not that its a bad thing, but he just seems like a dude that gets bored pretty easily.