They're machines that run on ziliujin. In the past they were uses for fighting or training but recently a new kind that help with farm work was developed. It has made the work easier but has also created new problems.

[Problems that should have been expected, he feels.

Also he was wandering because he sort of ran away from home. It's complicated.]

People who have never been responsible for such a thing tend to think only of the glory.

[Even he had made that mistake when he was still a child.] Were you a soldier?