Well, I sympathize with you. It's not really your problem. Maybe the other person is that careless character, don't take it to heart. In addition, personally, you seem to be the kind of person who likes to keep things in his heart. In fact, you have been in the same dormitory for so long. If he forgets next time, you can directly express your dissatisfaction and pretend to be angry. You don't know that you are all fellow villagers! Or you can say in a joking tone that people are from Jiangnan water town. Anyway, I don't think it's necessary for roommates to be so polite. If you have any complaints, you can just hit them. Hey, I wish I could help you.