If you are kind by nature, then you will not have a good life since you are old enough to understand.
Why? Because you can't protect your own interests at all.
Once the people around you find out your kindness, they will come to share your interests.
Even in elementary school, classmates will borrow things from you and not return them, or when they see that you have a good thing, they will find a way to take it over and break it for you.
This is human nature.
Until one day, you start to pay attention to your own interests. But at this time, you are still thin-skinned and don't know how to refuse. So you are still taken advantage of. But you already have a flame of dissatisfaction in your heart.
Later, through your own practice and constant competition, you slowly learn how to protect your own interests. But at this time, you are not selfish enough. You are still concerned about the interests of others. You just learned not to let them take advantage of you.
Finally, one day, you completely find the right posture.
Your wealth is also slowly accumulating.
From then on, you use self-centeredness to guide your words and deeds. Self-interest is the bottom layer and deep logic of all your actions.
At the same time, you also begin to evaluate the interests of others, keeping those that are beneficial to you and cutting off those that are not.