Most founders obsess over dashboards and aggregate metrics, but some of the best product insights come from understanding how individual users actually use their product. In this episode of Startup School, YC's @dflieb walks through one of his favorite tools for better understanding your users, the dot plot. It's a simple two-dimensional grid that reveals usage patterns no aggregate chart can show you. He’ll cover why it gives founders a better sense of product health, what patterns to look…