It takes a long time, personal perseverance, some help or pressure from outside, and so on. There are very few people who really do not change their personality at all. Some people (such as those with Asperger’s, schizophrenia, and paranoia) cannot change their personality and are pathological. The key is to change in what direction and to what extent. Many people change unknowingly with the general trend. It is not easy to truly grasp oneself and maintain an independent personality in a society with a cultural background like ours, not many. Many people are eager to change themselves in response to the scenario or to cope with the environment, which is very difficult, after all, people are not “chameleons”, they can change as soon as they say.