[The author is writing a very unusual protagonist]
What is one's true nature? It is following what the heart points toward and walking that path. But in this world, all kinds of things constantly interfere with one's true nature, trying to make one stray from that road. And the result is just that: the interference succeeds, one's nature shifts, and one sets off down another path.
Because in this world, there are things more important, things one must attend to, things that transcend one's own nature and carry a lofty significance. A good person can follow their true nature, stopping and starting as they please, as long as nothing unexpected happens. But when the unexpected does happen, they must also stray from their true nature to deal with the matter that is more important.
Because he is a person, someone who received a good education.
An original aspiration is something only a few people can possess. And he, evidently, is no longer one of those few.
It looks good, but the front is a bit too bland?