Just JavaScript by Dan Abramov

Just JavaScript by Dan Abramov isn't really a course about learning JavaScript. It's about rebuilding your mental model for it. If you already write JavaScript but sometimes feel like you're guessing at how things actually work under the surface, this is for you. The course is structured around a series of short modules, each focused on a single concept: values, types, equality, properties, mutation, prototypes. Rather than teaching syntax or walking through projects, it asks you to slow down and think about what's really happening when you write something like . The goal isn't new knowledge so much as clearer understanding of what you already know (or think you know). The illustrations and animations are a big part of what makes it work. Abramov (along with Maggie Appleton, who did the visual design) uses a "universe" metaphor where values are celestial objects and variables are wires pointing at them. It sounds a little out there, but it works. Concepts like reference vs. value, object mutation, and equality operators clicked for me in a way they hadn't before, and I think the visuals are a big reason why. Each module ends with a short exercise where you trace through code and predict the outcome based on the mental model you've been building. These are simple but surprisingly revealing. More than once I caught myself defaulting to an assumption I didn't realize I had. It's short (you can finish it in a few focused sessions) and it's not complex. But that's the point. Sometimes the most useful thing isn't learning something new, it's seeing something familiar more clearly.