"Old drifters" are a group of people who left their hometown to live in a strange place to support their children's careers and take care of their grandchildren. The environment here is unfamiliar, there is a lack of friends, there are differences in diet, climate and hometown, and they are very uncomfortable.
The intelligence gap, language barrier, difficulty in reimbursement of medical insurance in different places, and worry that their physical energy is insufficient and become a burden to the family are also problems.