The stupid rules. They are narrowed down so much by the Filthful and Disgraceful Slavebugger that they don't have time to think outside the pattern.
The witlesses' positive thoughts (what they want) include things like attending all the boasting sessions, reading the littera-trash, and pious-sneering. They waste so much time pursuing that rubbish that it leaves them no time to think outside. Their negative things include materialism, sexual variety, going online, and those dreaded apostates. That is what gets drummed into their minds at the a$$emblies.
Their music (if you are willing to call such sxxx "music") consists of 135 pieces of the worst imaginable rubbish that worships their own Filthful and Disgraceful Slavebugger. There are very few topics that their music spans, and those run the length of their boasting sessions.
The littera-trash is also rubbish. They are supposed to read the littera-trash, going by that instead of the real world. I have found that most of the littera-trash follows either the Adam-to-New-World story and some facet therein, or gives lists of rules and regulations. They have next to no variety in that, and they cannot fill in with outside sources.
Their activities are reading the washtowel along with the Not Well Translated Version of the Bible, praying according to their formula, pondering the things found in the washtowel trying to make it real to them, going to boasting sessions, and field circus. They do very little else--and if they do something else, Brother Hounder is going to put a stop to it.
When you are constantly pondering the same rubbish, your personality is going to be affected. You think of nothing except the Tyranny, you act toward nothing but the Tyranny, you read nothing except the Tyranny, and pretty soon everything you think, say, and do revolves around the Tyranny.