There is no simple answer to the question of whether a person who has committed a crime can completely change his bad habits. There are many factors that affect a person's ability to correct behavior, including personal character, upbringing, social support, psychotherapy, educational opportunities, etc. Some studies have shown that criminal behavior can be reduced through intervention and support, such as psychotherapy, education, and vocational training. In addition, a person's willingness to repent and expectations for future life also greatly affect whether he or she can change. If a person truly wants to change and receives appropriate support, many people can successfully change their bad habits. However, there are also some situations that may make it difficult for an individual to change. For example, lack of social support, returning to a bad environment, and mental health problems may make the process of rehabilitation more difficult. Overall, although the experience of committing a crime may have an impact on a person's behavior patterns, it does not mean that everyone cannot completely change bad habits. Everyone's situation is unique.