1. Dong Yu refused to teach him immediately and asked him to read it first. After reading it a hundred times, he would understand the meaning and knowledge.
2,3 Yu means that winter is the slowest time of the year (the first period), the night is the longest (the second period) of the day, and the rainy days are Usually the most difficult (the third remaining).
3. Original translation: Translation: A man named Dong Yu, also named Jizhi, has a simple personality, pedantic and studious. ...Some people wanted to learn from him, but he refused to teach easily. He said: "You must read the book a hundred times." It is natural to understand what it means after reading the book a hundred times. Those who studied with him said: "I want to study but don't have time." Dong Yu said: "We should do it three times a day." Someone asked what San Yu meant, and Dong Yu said: "Winter is the slowest time of the year." "The night is the longest of the day, and the rainy days are the hardest." Because of this, there are very few students who follow Dong Yu.
As for knowledge and understanding, it is already very clear. I hope the poster can experience it himself. Different people have different experiences. My experience is: the difficulty of learning, don’t use various reasons to shirk it. To defeat it, you have to squeeze out time by yourself. If you use a lot of free time, you will learn a lot, and you can conquer a lot of things and knowledge by yourself.