He's likely broke and needs the money. He once said that opening a night club was "being smart with his money"....
I seriously doubt it. He's made a decent amount of cash considering he never won a title and doesn't have a flashy lifestyle. Also got the impression he made some pretty decent sponsorship deals and i know he owns some good estate here in sweden. If he's broke, I don't know what he could possibly have spent his cash on living that quiet family life.
I think it's more driven by not being able to let go of the fighting + Can't stand leaving the game on such a lacklustre performance.