> Rational means you take the choice that provides the most value for yourself.

provides the most value over what period of time?

making every choice such that each choice, considered in isolation and unto itself, nets you the most value compared to what other choices would've gotten you at that same moment is analogous to best-first search. no one would say that best-first is the rational way to search for a path in a graph, because of all the ways it fails. so my question is, if there's one of those tragedy-of-the-commons situations that happens all the time, why do we insist on saying the participants are acting rationally when they are, metaphorically, walking into a wall forever?