This world is made of one after another ordinary person.
We live in such a world. So we have to constantly communicate with different kinds of people.
And where there are people there are all sorts of different rules that come with them.
Some of these rules are written.
The others, however, are hidden in the dark waiting for smart people to find them out.
This is not the dark side of this society. It's just the natural result of human interaction.
We can't live in a world ruled completely by solid rules. A world like that is hell. And it will make our civilizaiton stagnant.
If we are to make our civilization develop, we have to activate that flexibility that makes us human.
And this nature, this soft nature, will inevitably bring a lot of rules that stay unseen.
So, right, from this perspective, the world is cruel .
But this is the world that you live in.
Only by doing this can you live on.