This is a personal question, which means that only you can provide a full answer to it. However, we can provide an example that can help you guide your work.
It is true that some people, and even very intelligent people, do not necessarily think critically about all issues. While people might be rational in most subjects, they can sometimes be reluctant to think critically about controversial subjects, such as politics, religion or the supernatural.
A common reason for this is that people attach emotional value to such subjects. They might unconsciously connect such topics to feelings of hope, inspiration, happiness, or faith. Often, people are scared to question these topics because of the fear of losing the emotion that they have attached to it.
Another common reason is that people often avoid critical thinking in these topics because such ideas have become too internalized. They might be a core part of the person's identity or upbringing. Therefore, people might not be able to have objectivity when it comes to the idea. Alternatively, they might also not recognize the need to think critically about such subjects.
