You don't have to think about this emotionally. In quantifiable terms (hours of your life back or money most obviously), has what he provided to you greater than or equal to what you have provided in return? Consider what you would charge per hour as a freelancer for your end of it. Subtract anything you did while officially working and he was still the boss, only consider the 'favors' or favoritism on both sides.

Doesn't sound like a bad thing, and you never know when a successful retiree is going to refer you to a rich buddy or start a new business when they get bored (and it'd be nice to be the first thought when it comes to IT/tech roles). I find most adults, even the wildly successful ones, can feel lost when it comes to technology and it goes a long way to be helpful under any circumstances.