Selfishness has a healthy mind. To put it bluntly, we should be enterprising, proactive, willing to work hard and bear hardships.
Kindness is not complicated, which means that a person should have a kind heart, and people who encounter difficulties should know how to help others and do things with a positive attitude.
Don't think too much, make enemies. People should know how to be content. Get along with people without extremes, without minor disputes, and get along well.