the.com/sunk cost
the money's already gone; only your ego thinks staying will bring it back.
means a past cost that cannot be recovered, so it should never factor into a rational decision about what to do next.
from formalized in economics and game theory in the 20th century, though the trap is ancient — every gambler doubling down to win back losses has been doing it for millennia.
also calledthe concorde fallacy, after the doomed jet
animals dodge itrats and mice largely ignore sunk costs
humans don'twe escalate commitment specifically to justify past spending
real fixask only what future costs and benefits remain