Do they really “ know “ it’s not true?
Some , perhaps but the majority of long time dubs get beyond thinking of that . After many decades and social exclusion from the real world, that is no longer an issue… it is a part of them ,they cannot imagine life without it . In a way they don’t care any more because they are so wrapped up in following the ‘slave’ that it the question no longer matters.
There was an old maxim that used to be common.. they said “ it is better to be wrong & inside the Truth than to be “right outside “ it ….