In the real world, there are many people who plot against you, most people who are indifferent, most people who step on you when something goes wrong, most people who will go crazy or even risk their lives for money, most people who don't want to see your good deeds, and most people who do evil things behind your back. Most people.
They are not taught in these books because they are too realistic.
If you compile a set of teaching materials on human worldliness, warmth and warmth in the world, just imagine how many people would be able to graduate?