Sunk Cost .vs. Opportunity Cost

Wikipedia definition
sunk costs are retrospective (past) costs which have already been incurred and cannot be recovered.
Opportunity cost is the value of the next best alternative foregone as the result of making a decision.

OK~sunk cost should not be considered when making a decision whereas pportunity cost SHOULD be considered. sunk cost is cost already spent in the past, and opportunity cost arises after some decision is made(or at least right before the decision is made). I see that sunk cost and opportunity cost are two very different costs.

Now, let's apply to my life.

next February, i am going to KAIST MBA. what's the sunk cost? two years of working at samsung sds to fulfill the requirement, which was not really much of fun. how about my opportunity cost? At first, it seems there are a lot of opportunity costs related to going to MBA course, like not getting paid for next two years, two year behind in my career,loosing my social status and so forth. however, the definition of opportunity cost is the value of the 'NEXT BEST' alternative. so it should be a single thing that i am actually giving up. then it narrows to spending two more years in samsung sds- again, where i didn't enjoy much.

conclusion!

huge sunk cost(if you think about all the hardship to get a job at samsung). minimal opportunity cost. what should i do?i should start MBA course.

but is it that simple?

first of all, can i really forget all about the sunk cost and move on? NO. I graduated from YONSEI University and i can't go to school with lower rank. my colleagues from samsung usually earns this or that amount of money - it should be guaranteed that i earn more money after i finish the course. bunch of cost-effective problems arise. there are more complex problems on opportunity costs. it would be clear to rank the possible choices if we see them as a whole for each choice. but if we rank them in various measures, there can be multiple opportunity costs therefore costs accumulate. even though opportunity cost from measure A and opportunity cost from measure B usually can't co-exist, we tend to ignore this fact.(earning more money(measure A) by staying in samsung and preparing for top MBA extra year and then going to HBS(measure B) cannot happen at the same time)

SUNK COST?

OPPORTUNITY COST?

all of a sudden, i am dragged by the sunk costs and haunted by the opportunity costs.

come on~ you stupid.let's go back to the basic.
the sunk costs cannot be accounted and only one opportunity cost can exist - staying in samsung, yuk.

conclusion again.

It is right in my heart to go to MBA. and it is economically right to go to MBA.