Is it Otaku if it's a useful skill or hobby? I mean, cooking for example. Maybe being a gourmet can be an otaku, like being able to distinguish different types of rice by taste alone, that's pretty weird and obsessive. But if you're a passionate chef, and make a living off of it, does that make you otaku? I always felt that in order for it to be otaku, it not only has to be passionate and extreme, but also, useless.