I don't think this is downvote-worthy, even if it is something of a personal opinion. Heck, half of what transpires for discourse on HN technical topics boils down to personal opinion. On days when I am being cynical, I think that the phrase "Best practices say that" is a veiled synonym for "I prefer that", for example.

This thing -- that different rules get layered in inconsistent ways that cannot easily be algorithmized -- is indeed an inconvenient part of adulthood. But it is a subset of an even more difficult problem. Shermer put it this way, that "smart people are very good at defending beliefs which they arrived at by non-smart reasons." Perhaps the most jarring studies proving this happen on split-brain patients -- people who, because of for example seizures, had a medical procedure where their corpus callosum was severed and now their two halves of the brain cannot talk to each other anymore. Some studies of such patients document trying to prompt their right half of the brain to do something, then verbally ask the left half why they are doing that thing. The shocking thing is that they usually do not get some "I don't know" response from the left-brain; they apparently usually get a comprehensive justification of the action complete with all sorts of details except for the crucial one ("I did it because you asked me to"). So like if the behavior was standing up they will explain how they felt uncomfortable about sitting too long and needed to stretch their legs, but the actual reason was that the experimenters asked the other half of their brain to stand up and it felt agreeable to that suggestion.

Justification is in other words something that we generally backtrack to find. And this in many ways kindly resolves the problems of inconsistencies. Because a better way to look at it is that we have various values which our actions can either serve or betray. Those values are not perfectly orthogonal, and thus alien to any sort of conflict: rather, certain actions will invite you to trade off your value of (say) living an ambitious daring life of adventures with the value of (say) being compassionate to others. So if you were to have an affair you will need to evaluate a moderate betrayal of your value of simplicity/honesty and a large betrayal of your compassion (and if you have this value a massive betrayal of your humility and self-vanishing) for a minor benefit to your curiosity and a moderate benefit to your risky ambitiousness. All of these values come in to speak a separate statement over that choice, and the judgment must be made by you-as-judge to weigh whether the benefits are worth the costs. [This particular schema of five values was in fact the result of a large amount of introspection in my more vulnerable years but now I am not sure that I find it correct -- but it is still useful for this discussion I think.] In my case my judgment is simply that I'd lose way more than I'd gain, so cheating is immoral -- and not just immoral "for me" but that in my ideology pretty much everyone will lose way more than they'd gain, so that "all other things being equal" it is immoral to cheat on your spouse. And indeed if these values are objective, as we have some reason to believe they would be -- like, human biology just functions better if we can generate societies, and those societies just function better if they can have values such as these -- then objectively cheating is immoral. So the fact that we can backtrack from our actions to our values and weigh those actions with those values really frees us from having to somehow "orthogonalize" our values into nonoverlapping Kantian precepts that might hopefully never conflict with each other and generate a logical derivation of what we should do, "People should never lie unless they are saving folks from Nazis or they are preserving the surprise of a surprise party or... or... or..."