Why did the protagonist regret after helping Mr. M. ?

It is understandable and probably universal that human beings always hesitate when deciding whether to help others at the cost of their own personal benefits. Human beings are complicated and they are at the same time, both self-centered and altruistic. Besides, most of the time human beings’ desires are unlimited and they always want to have more. Even if the protagonist were not as poor as he is in the book, he would still feel somehow reluctant to help others. The second reason might be that the protagonist comes to realize that, as long as the private property system still exists, poverty would not be cracked down. Probably the rich would become the poor, but there would still be a huge gap and it would expand as the economy develops. Therefore, his little favor would not change the situation. Even for Mr. M., it cannot change his destiny. This is the same reason why i refuse to help a beggar. Regardless of their purpose and state of mind, as long as it is not an emergency, i would refuse to help them. Even though the poor are pathetic and i feel miserable for them, it is the necessary result of the social system and the historical stage of development that we nowadays are at. Helping the beggars would not always lead to the envisioned results, but would probably lead to the bigger miseries.