Why do Koreans use 우리 to mean my?
Koreans like using 우리 to show a sense of community, but not always between them and the speaker. In English when you say ‘I went to our house’ it typically means 1 of 2 things; you and the listener live together or the person you live with is with you. Korean includes another option where nobody living with you is there; nobody even needs to live with you!