Why do so many people constantly overthink? Essentially, it’s because the brain is inherently a "prediction machine"—when information is uncertain or lacks clear feedback, it automatically fills in all possible scenarios to reduce anxiety about the unknown. But the real problem is that modern life is filled with information noise and uncertainty, and the brain lacks the clear boundaries of the primitive environment where "once a problem is solved, it ends." As a result, thinking easily falls into repetitive reasoning and self-cycles. At the same time, when a person lacks clear next steps for action, thinking is used as a substitute for action—instead of solving problems, the mind just keeps simulating them, and the more you think, the more tangled it becomes. So, instead of solving problems in your head, turn problems into: factual verification, smallest actionable steps, and clear stopping criteria.