Even members of the Church of Scientology who know of Xenu will publicly deny the existence of space-opera doctrines, or attempt to minimize their importance. Scientology has many graduated levels through which one can progress. Many who remain at lower levels in the church are unaware of much of the space-opera doctrines, which mostly begin at Operating Thetan level three, or "OT III". Because the information imparted to members is to be kept secret from others who have not attained that level, the member must publicly deny its existence when asked. OT III recipients must sign an agreement promising never to reveal its contents before they are given the manilla envelope containing the Xenu knowledge. It is knowledge so dangerous, members are told, that anyone learning this material before he is ready could die.
After reading this stuff today I feel a little bit like I might die.