You help a weak person, and he won't be grateful to you. He doesn't care about being grateful, and some might even stab you with a knife; this is human nature. Why are the weak weak? It's because they don't understand gratitude. Because they don't understand gratitude, strong and capable people will leave them, because the stronger the person, the more they want to be repaid. Those who don't want to repay cannot be strong or capable. There is no return from the weak, so the strong have all left. In the end, around the weak, there will only be a group of even weaker people, and they will become weaker and weaker. The path of the weak is dominated by themselves; this is the way of humanity and also the way of heaven. The broken ones are precisely those who are grateful, who allow others to have returns.