Elsa sings that “the past is in the past”. She’s had an affliction – being able to turn things into ice. (I think many people would claim they’ve had exes for whom that applies … but for her this is literal!) But the fact that she’s had a past shouldn’t influence what decisions she makes going forward. Elsa’s past is a sunk cost. The only thing that should influence a person/firm’s decision to move forward is the expected benefit/loss from each alternative action.