I typed "Clean the kitchen" into a chat box. A robot turned toward the right room, drove over, swept the floor in a tidy back-and-forth pattern, and came back home, while describing what it was doing the whole way. No buttons, no coordinates, no code to write each time. Just a sentence. I built this over the last few weeks. It's called NavMind, and it's the first project I'm writing up as I learn robotics in public. Here's what it does, the one idea that makes it work, and the things that broke along the way. What it is, in one breath NavMind is a robot that lives in a simulated house. You tell it what to do in plain English, and it figures out which room you mean, drives there on its own, cleans the whole floor, and returns to base. There are six named rooms: kitchen, bedroom, study, and so on, and it handles commands like "vacuum the bedroom" or "sweep the guest room." It runs entirely on my own laptop. No cloud, no paid API, no physical robot, just a simulator and a language model running locally.…