43

43 February 19

    Having forgotten to clock in a course,I had to charge fee for the course that could have been free of charge, making me feel a little regretful,which let me realize the true meaning  of the word opportunity cost,a concept in  microeconomic theory,that the opportunity cost of a choice is the value of the best alternative forgone and the sunk cost is not cost.If a person have bought a movie ticket,he goes to the cinema and sits down,only to find that he doesn't like it all,then the wisest decision he should make is just going out,avoid wasting any time.But for most of us,we will stay there and don't leave until the movie ends.

    Like the hero from the story,under no circumstance should I put the things that can't be changed in mind,beacuse sunk cost is not cost.