Shim Chung and Yi Soon Shin

I think it is very important that Shim Chung and Yi Soon Shin are mentioned as the great example of filial piety and loyalty.

Look carefully.

Shim Chung didn't follow what her father said (or wished) in order to save her father. What if she just obeyed what father said, then eventually father dies.

Yi Soon Shin did not obey the King because he knew that would mean the defeat. What if he just obeyed what the King said, then his country would be defeated.

But, I don't think they made the decision very easily. They must have struggled a lot; whether to take a temporal satisfaction of following their subject, or to risk losing their trust for the moment in order to eventually truly contribute to them.
There must be a lot of unspoken pain and tears involved in their decision.

The level of their filial piety and loyalty was beyond just obeying their parent/king. Their level was for the sake of the benefit of the whole (father's purpose, King's purpose), they were willing to even lose their pride or being temporarily misunderstood (and considered unfilial or a traitor)

The amazing thing is that they didn't stop in the middle, but they went all the way to the end. They didn't receive the recognition for their filial/loyal act during their life in this world.