A few days ago, at a gathering of friends, I chatted with an old colleague about the situation in his new department. He said with deep feeling: "Don't say, 'self-study' is really poisonous chicken soup sometimes. The more you drink it, the more addictive you become." While talking, he opened his circle of friends and said, "you see, he has been responsible for equipment maintenance for half a year. In his circle of friends, he clocks in online courses every day, works overtime...