The reason is that the author is the only China student in Sendai, and the locals regard him as a rare figure. It is precisely because of his rarity that he attracted the curiosity of school staff and gave him more care and help, which is an understanding. However, it should be understood in a different way. The preferential treatment for Sendai is of course out of the friendly feelings of the Japanese people. Most ordinary Japanese are kind and friendly, especially those from poor and backward China. However, the author is unwilling to accept their care, preferring to regard their care as "things are rare and expensive". "Probably" means that there seems to be such a thing, but it's not entirely certain. Used with "ba" at the end of a sentence to strengthen the uncertainty of tone. This is why the author speculates that he is "favored" in Sendai in a humorous tone, and thinks that Japanese friends care about themselves out of sympathy for the nationals of weak countries, not respect. For Lu Xun, who has a strong patriotic feeling, he naturally feels infinite bitterness.