I used to have a very self-disciplined teacher. She had four classes in the morning. Every class, she has to do exercises in the corridor alone and take the school bus. She had to do exercises a few minutes before the bus left, and no one was watching. Class ends at 5: 30 pm and the school bus leaves at 6: 00. She always spends half an hour cooking dinner, saying that she has already finished eating and has to write an article when she goes home. She never looks at the taste when eating, and always matches it according to nutrition. What she eats most is corn. The point is that she has lived for decades, which is terrible.