Of course, all writers get that. My added benefit is that here there are also artists who build those worlds and programmers who give me an engine to walk through it. Unless you've done it, it's not an experience I can really describe. It's something I'm grateful for and really enjoy. Get your core stuff down.
Writing is a natural ability that reading and school can enhance.
Role-playing systems are more complex. Try your hand at DMing a game. Learn how and why something works. Game design is the elusive one. I learned what I know through many years of apprenticeship, I guess, working with other designers.