Talmud

The real sting of this wisdom lies in its reversal: we rarely suffer from poor eyesight so much as from poor self-knowledge. A pessimist observing a setback sees confirmation of failure; an optimist sees opportunity—and they're genuinely perceiving different things, not just interpreting the same facts. This explains why two colleagues can attend an identical meeting and leave with entirely opposite accounts of what happened, or why the same marriage looks like imprisonment to one person and sanctuary to another. If you want to see the world more clearly, the Talmud suggests, the real work isn't getting better glasses—it's becoming the kind of person who can look fairly.