There are many reasons why the characteristics of the people in Fanghua's movie have changed. The following are some of the possible reasons: - Changing times: The protagonists in the movie have experienced different times, from China in the 1950s to China in the 21st century. People's lives, values, and concepts have changed. These changes could lead to changes in the characteristics of people. - Different social backgrounds: The protagonists in the movie come from different social backgrounds such as rural areas, cities, the army, etc. These social backgrounds may cause people to change their characteristics. - Different personal experiences: The protagonists in the movie also experienced different personal experiences such as war, separation, growth, etc. These experiences could lead to a change in a person's characteristics. As for the reason why there were no changes, there were a few possibilities: - The characteristics themselves had not changed: the protagonists in the movie were still people with firm beliefs, a sense of justice, and a sense of responsibility. Although they had experienced changes in times and social backgrounds, their characteristics had not changed. - The era and social environment have not changed: the era and social environment of the protagonists in the movie have not changed, and their characteristics have not changed because of the changes of the era and social environment. - Different personal choices: The protagonists in the movie may not completely change their characteristics according to the expectations of the times and society. Instead, they shape their characteristics according to their own values and personal choices.