Why are some people afraid of the truth?

First, what many people fear is not the "fact itself," but the impact of the fact on their self-perception.
Accepting the truth means that it might have been wrong all along, or even require overturning their original stance and self-image.
Second, the truth is often not a single sentence but a complex chain of cause and effect, and the brain has a "cost-saving tendency," preferring simple narratives and quick judgments.
It's not that it doesn't think, but that it is unwilling to bear the thinking costs.
Third, the truth will break people's "psychological safety zone."
People are used to believing that the world is controllable and that they are rational, and when the truth conflicts with this, it can bring a sense of loss of control and shame, leading to instinctive resistance.
Fourth, the truth has a certain "heart-shattering" power.
It not only points out that you are wrong but may also reveal why you were wrong—those unacknowledged motives, emotions, and herd mentality will be exposed.
Fifth, accepting the truth often comes with real costs, including group pressure, relationship risks, and the cost of changing one's stance, making "accepting the truth" no longer just a cognitive issue but a choice to bear consequences.
Therefore, for many people, avoiding the truth becomes their "safest" path.