The reason it is bad is that you will lose control of it. Even if you have a handle on the truth now you will lose it if lying for the sake of narrative is expe

The reason it is bad is that you will lose control of it. Even if you have a handle on the truth now you will lose it if lying for the sake of narrative is expected and widespread and nuanced discussion is suppressed to avoid hurting you cause. What you lose is ability to detect when it is time to change the cause (because it is fixed or something else even worse comes up or unintended consequences are uncovered). It is akin to setting a course and then closing your eyes as to avoid any distractions on the way.