Every product team has a theory of the user — a mental sketch of who they're building for, what that person wants, and why they behave as they do. The danger is not that this theory is wrong. The danger is that it becomes invisible. The 18th-century Neapolitan philosopher Giambattista Vico argued that we understand only what we have made — *verum ipsum factum*, truth is the made thing. He meant this as a victory: humans can fully understand history and culture because we constructed them. But there's a shadow side he didn't dwell on. When you've built something, you can no longer see it from outside. The builder's intimacy becomes the observer's blindness. Product managers live inside this shadow constantly. You build the onboarding flow, the mental model of the confused new user, the story about why retention is dropping — and then, because you made it, you mistake it for reality. The corrective isn't more user research (though that helps). It's the discipline Vico himself modeled: treat your own constructed framework as a historical artifact, something made in a specific moment under specific pressures, not a transparent window onto the world. Ask what assumptions were load-bearing when you built this model, and whether those conditions still hold.

Pick the user assumption your team treats as settled fact. What specific event or conversation originally produced it, and how much has changed in your product since then?

Drawing from Neapolitan Historical Philosophy (Vichian) — Giambattista Vico — Scienza Nuova / New Science (1725, revised 1744)