There are roughly three types of relationships between people. The first is a pure transactional relationship: buying and selling, cooperation, resource exchange, emphasizing clear reciprocity and direct exchange as the most efficient. The second is a reciprocal relationship: friends, colleagues, where there is mutual feedback but not immediate settlement, requiring time and interaction to maintain. The third is an emotional relationship: close bonds, deep friendships, sometimes even one-sided giving, and this imbalance is precisely the essence of emotion. In reality, most people mainly face transactional and reciprocal relationships throughout their lives. If everything is measured by equivalence, we can indeed hurt less, but we might also miss out on genuine acts of selfless sincerity. Perhaps sincerity itself is a low-probability event. Truly mature boundaries are not about refusing exchange but about learning to distinguish: which relationships are suitable for direct equality, and which are worth gradually building trust.