imagine every instant in your life is an infinitesimally small point on a timeline (or every millisecond if something concrete is easier). the present is t0. a

imagine every instant in your life is an infinitesimally small point on a timeline (or every millisecond if something concrete is easier). the present is t0. an event occurs (buy ticket) at tX. according to "ignore sunk costs", at tX+delta you should annihilate all influence from any event at tX or before. therefore that you have a concert ticket is, in a weird way, almost immaterial. it enables a future decision (to "freely" go to a concert, as you would any other activity) but, my interpretation is that you only have present and future after every instant moment. you may say: well what about eliminating future opportunities? e.g. i spent my last $250 on concert ticket so can't go to hawaii. that is in part of a matrix i would call "regret" or counterfactuals (not sure if there's an economic/scientific term here), which involves thinking about how past decisions affected future ones.