There are bound to be some people that we meet in life that we just don't understand. In Noona's life, she totally does not understand why some people love to work overtime. Even though we know that bosses' expectation lead to occasional "no choice but to work late" scenario, actually deep down, the decision is taken by the individual itself. Okay, maybe they need to work late to maintain good impression of themselves and hence, their career. 

But what makes Noona even more confused is why let's say exhibit A who is a pretty woman, young, live comfortably (parents are quite well off, Noona believes she has her own comfortable bedroom, etc), have a quite handsome boyfriend, at pretty high rank for her age, have enough (and even a lot of) money and yet STILL WORK LIKE CRAZY (by crazy here is spending more than 12 hours in average of her career life). Noona just can't understand it. 

But after a few moment of consideration...

She decided not to use this kind of exhibit as a benchmark and live her own life in her own comfortable way. 

The end.