Medieval Jewish philosopher Maimonides drew a sharp distinction between two kinds of ignorance: not knowing something, and not knowing that you don't know it. He called the second kind the deeper danger — not because it feels bad, but because it feels fine. The mental model problem for experienced leaders and PMs isn't usually missing a framework. It's that the most load-bearing models — the ones structuring how you read your market, your team, your users — have become so fluent they're invisible. Fluency mimics truth. When you reach for a model without noticing you're reaching, you've crossed from using a tool to inhabiting an assumption. Maimonides's prescription was specific: the path out of compound ignorance begins not with acquiring new knowledge, but with a sustained effort to locate the boundary of what you currently understand — the exact edge where your confident explanations thin out into gesture. For a PM or leader, that edge is almost always traceable: it's the question you redirect in a meeting, the metric you stopped interrogating, the team dynamic you've explained the same way for eighteen months.

Which explanation do you give most confidently, most automatically — and when did you last genuinely pressure-test it against a case that didn't fit?

Drawing from Medieval Jewish Philosophy — Moses Maimonides (Guide for the Perplexed, c. 1190 CE)