What exactly do you mean by 'satisfied'? I do believe that Socrates (as he is typically portrayed) was immune to dissatisfaction. I do believe he even said this himself by way of "you cannot harm a virtuous man".
In the pig's case (I take it that you mean a glutton), I would argue that long-term indulgement in immediate pleasures leads to a very dissatisfying life. That pie may taste good, and sitting on your bum may feel good, but how will you feel in the future? Especially compared to someone who ate healthy and exercised (I think this character could parallel Socrates in some regard [by that I mean he is "dissatisfied" with having to run in the morning, skipping the 2nd slice of pie, etc, but continues to do it anyways, because it's what's best (like virtue)]).
So yes, I agree with Mills.