I've seen some people with a full-blown psychosis.
They generally believed inconsistent, blatantly easy to falsify stuff. On one hand, say, persecutory delusions are unpleasant, but stopping to believe them unconditionally leaves one with how their life sucks and then they're lost with so much distress, that relapsing isn't that bad of a result...
It's bad for anyone to second-guess their thoughts, dreams, ideas, etc. and blaming oneself for them. One thing's not losing judgement, but TOO MUCH self-control is even worse! The resulting anxiety skyrockets, then it gets worse.