I think it helps to distinguish moral injunctions from statements about human preference. First are the heuristics, while latter are the statements of truth. A "position" is a heuristic, but it isn't necessarily the right thing to do, in some of the case where it applies. Generalization from personal experience may be useful on average, but doesn't give knowledge about preference with certainty. When you "follow you own utility", you are merely following your imperfect understanding of your own utility, and there is always a potential for getting the map closer to reality.