I used to travel alone when I was doing projects, and all of them were long-term (more than half a year): 1. Loneliness: there is no problem in the place where customers work normally, so they can concentrate on their work, but when they return to their residence at night, especially when they don't need to go to work on weekends, they are particularly lonely. I don't have anyone to talk to. I can call a friend for an hour or two. 2. gain weight: three meals a day, eat the customer canteen every day, and the customer's food is good. I once gained ten pounds in a central enterprise canteen for half a year and didn't like sports very much; 3. Save money: in the second-tier provincial capital cities, just graduated from work for two years, and the down payment on the house is enough; 4. my health will get worse: because no one cares about you, I will muddle along. I once stayed in a factory dormitory in Guangzhou for a winter and suspected that I had rheumatic bone pain.