Nanjing Massacre--problem between Chinese and Japanese

The hatred between Chinese and Japanese seems to last for a very long time. Like I said before, when Japanese were suffering from Earthquake, the Chinese were celebrating the disaster that destroyed Japan. Why? The Nanjing Massacre is the most common event that the  Chinese bring up. They can't stand that the Chinese governments treat Japanese nicely after they slaughtered hundreds of thousands of Chinese. Chinese, especially people over 70 years old, hate the Japanese, because they cannot forget how the Japanese soldiers were during that 6 weeks of holocaust. I understand their hatred, because they've been through all these things. What I think is ering is that right now many Chinese teenagers hate because of the hatred. They cannot feel the pain that others suffered. They just hate everything, and what the Japanese did is only a good excuse for they to hate. I cannot feel the pain that these old people had suffered from, I cannot understand how much cruelty they've been through, but as a bystander, I would like to say to the Chinese new generation that we must remember the history, and forget the hatred. We can't let these kinds of things happened again.