What does the human stain mean?

The stain of human nature, I think, may be the opposite of the prominence of human nature.

The highlight of human nature is what we hope others can do, kindness and diligence.

But we often don't ask ourselves this way. We are often unfriendly and lazy.

Therefore, the stain of human nature can be said to be unkind and not diligent. That's not enough.

But doing things is too kind and there is no way out, okay? I worked too hard, and I'm exhausted, okay? This is too much again.

Not so good, not too much, all stains. What are we doing? Mean. The most valuable thing in China's culture for thousands of years is the golden mean.