The five-word famous sayings of celebrities are: aim high (Zhuge Liang), be brave when you are ashamed (Kong Qiu), be a friend when you are in trouble (Lenin), stick to the truth (herzen), review the past and learn something new (Kong Qiu), and think twice before you act (Kong Qiu). The explanation is as follows:

1. It is Zhuge Liang's famous saying to aim high, which means that people should have lofty aspirations and ambitions. This sentence tells us that only by setting lofty goals and ideals can we keep moving forward and constantly surpass ourselves. At the same time, it also reminds us not to be confused by the immediate difficulties, but to strengthen our faith, go forward bravely and pursue higher realms and greater achievements.

2. Knowing shame is almost brave, which means that when a person realizes his mistake or shame, he may feel very sad or guilty, but at the same time, it will also inspire his courage and determination to change his behavior so as to avoid suffering the same shame again. This kind of courage and determination can make him more self-disciplined, firm and hardworking.

3. The saying that adversity is a friend comes from Russian revolutionary Lenin, which means that in difficult times, friends will be more closely linked and face difficulties together. Lenin emphasized the importance of friendship in his book What to Do. He believes that during the revolutionary period, there are many difficulties and dangers, but only those who can unite can win.

4. Reviewing the past and learning the new is a sentence from Kong Qiu's Analects, which emphasizes the importance of reviewing knowledge. By reviewing what you have learned, you can not only deepen your understanding of the original knowledge, but also discover new ideas and inspirations. This process of learning the new is based on reviewing the old. Only by deeply understanding and mastering the old knowledge can we better understand the new ideas and ideas.

5. The meaning of this sentence is not simply to hesitate for three times before taking action, but to think carefully as much as possible before making a decision or taking action to avoid the negative consequences caused by impulsiveness or recklessness. At the same time, we should flexibly adjust our thinking depth according to the specific situation and environment, and neither blindly rush forward nor hesitate too much.