A man watches with horror as a tree begins to fall onto the car containing his young son. He rushes to push it aside, but he hasn’t been exercising since college; his strength fails to move the tree, and his son dies as a result.
Going to work, the same man in a different universe quite clearly remembers dropping off his young son at the daycare, and so leaves his sleeping son in the car through the broiling summer day. This is, unfortunately, fatal.
Our first instinct, as a society, is to assign more blame to the latter man than to the former. It’s one thing if you just don’t have the strength, but surely anyone can remember something?
Well… no. Even if our brains were so convenient as to remember important things better than trivial matters, there’s lots of literature suggesting that, for example, willpower is a resource. On top of, say, indications that intelligence is to some extent inherent, even if it’s often overwhelmed by nurture-factors (not all of which are under the person’s control)…
Of course, this isn’t to suggest we stop holding people responsible. Purely on game theory grounds, that would be rather disastrous. But we should be aware that, in a rather D&D-esque fashion, we are judging people who “failed a will save”, whose intelligence-statistic simply wasn’t high enough for the situation – not someone who somehow chose, with something not their brain – their physical brain, affected by nutrients and genetics and early development – to ignore their “platonic self.”