For some reason, i actually believe him. Punk doesn't strike me as somebody who's going to stick around for years and years and hang on just for the hell of. Seems like somebody who saved a lot of his money and has other interests outside of wrestling.
He's said he wants to retire early in at least a few interviews I've seen from him. I believe him. Since he's straight edge he can't even medicate his injuries the way that a lot of guys do, so he is out there in pain every night. I wouldn't want to do that until I was old and grey. Plus, he got his girl wifed up on the road with him. You know that shyt isn't gonna last.