Trump's latest theater of the absurd regarding Schiff is that he now suddenly claims that Schiff made up all the whistle blower's allegations himself...
No matter that the whistle blower complaint accurately described a telephone conversation that Schiff could never have read until Trump released it three weeks ago.
It just gets more and more surreal by the minute.
If you lack motivation to challenge your own perspectives on something, then all it takes is some piece of information to resolve an exposed discrepancy and move on. There is no need to then fact check it, remember that information, and cross-reference it with other information past or future unless the new information substantively changes the narrative you are inclined to trust.
Truth is, this is normal operation of the human mind. It is productive social behavior. There are so many things out there that we couldn't possibly understand all the details of the things we know. So we don't do around questioning everything we think we know. That's because we are social creatures and trust that, if something does come up which exposes a gap in that you think you know, you can always turn to the trusted others to fill those gaps. Such as good old Google. Or your doctor. Etc.
The critical problem is we're also programmed to group together based on shared perspectives/cooperative intents. Thus, what we recognize as a trusted source isn't strictly related to their underlying trustworthiness. It is only when a discrepancy in that trustworthiness is exposed which can't be repaired without altering the established narrative that we tend to question if we've misplaced our trust. After that happens, in fact, it can be hard to reestablish the lost trust even even we learn that our reasons for questioning the trust were misguided. This is why conspiracy theories and other misinformation campaigns are so toxic. The implications they carry tend to stick if we ever attached our understanding to them even after they have been exposed as patently false.
This behavior is understandably productive in a tribal society. If challenging the way of life of your own group leads to you being excommunicated and not accepted by the other groups in exchange, then it wouldn't be very productive behavior to engage in very often. Yet there does need to be mechanism for change, and this is more likely accomplished through regime change/revolution than any kind of reasoned evaluation of reality.