An Easier Guess

"I noticed something else," Jiang Yao said. "The person's body stiffened for a second when the waiter handed them the coffee on the table. The hand beneath the table shifted. He was about to drink coffee when he averted his sight. For a long time, his eyes were fixed on the other person at the table. He was watching how other people sipped their coffee. Therefore, that guy had most likely never encountered such an occasion before today. He was nervous because he had not seen much of the world. He was nervous as I passed by him. I was nervous as well when the waiter brought me coffee. Finally, he decided not to touch the coffee. He was probably terrified of making a mistake and being caught out, or of being mocked by others."

"Can you guess what that person does for a living? It should not be easy to guess, right?" Colonel Lin replied.