Of course it takes a lot longer to prep all the veg - strips of carrot and courgette for support splints, finely chopped salads, tahini and wasabi sauce, and that's not to mention the growing of all the veg, and the harvesting, pounding and drying of the kelp to make the nori sheets themselves...
And it always takes less time to eat it than it does to make it...
Anyway, enjoy...