Why North Korea soldiers so devoted?

It is said from some Chinese media that North Korea launched a series of military  exercise warn South Korea and the US. In the military exercise, they "occupy" Seoul the capital of South Korea in three days and jailed lots of Americans.

Well, it is understandable. You can see those North Korea soldiers all excited and devoted, the reason is simple: they were rushing to the South, come on, they were to arm food and freedom, how could they not be excited and devoted?